Printhead capping arrangement

ABSTRACT

Microelectromechanical pagewidth printheads include a very large number of ink ejection nozzles fabricated upon a silicon wafer. Ink stored in the printhead subsequent to a printing operation is vulnerable to becoming undesirably viscous thereby causing inconsistent printing. In order to address this problem the present invention provides a printhead recapping mechanism. The mechanism includes a base portion, that includes a solenoid coil and a movable capping portion which incorporates magnetically attractive material responsive to the coil. A spring biases the capping portion to a quiescent capping position when the printhead is not in use. During printing operations a current is applied to the solenoid coil to overcome the biasing spring and draw the capping portion from the capping position.

CROSS REFERENCE TO RELATED APPLICATION

This is a Continuation of Ser. No. 10/729,157 filed on Dec. 8, 2003 which is a continuation of Ser. No. 09/112,774 filed on Jul. 10, 1998 all of which are herein incorporated by reference.

FIELD OF THE INVENTION

The present invention relates substantially to the concept of a disposable camera having instant printing capabilities and in particular, discloses a printhead assembly for a digital camera system.

BACKGROUND OF THE INVENTION

Recently, the concept of a “single use” disposable camera has become an increasingly popular consumer item. Disposable camera systems presently on the market normally include an internal film roll and a simplified gearing mechanism for traversing the film roll across an imaging system including a shutter and lensing system. The user, after utilizing a single film roll returns the camera system to a film development center for processing. The film roll is taken out of the camera system and processed and the prints returned to the user. The camera system can then be re-manufactured through the insertion of a new film roll into the camera system, the replacement of any worn or wearable parts and the re-packaging of the camera system in accordance with requirements. In this way, the concept of a single use “disposable” camera is provided to the consumer.

Recently, a camera system has been proposed by the present applicant which provides for a handheld camera device having an internal print head, image sensor and processing means such that images sense by the image sensing means, are processed by the processing means and adapted to be instantly printed out by the printing means on demand. The proposed camera system further discloses a system of internal “print rolls” carrying print media such as film on to which images are to be printed in addition to ink to supplying the printing means for the printing process. The print roll is further disclosed to be detachable and replaceable within the camera system.

Unfortunately, such a system is likely to only be constructed at a substantial cost and it would be desirable to provide for a more inexpensive form of instant camera system which maintains a substantial number of the quality aspects of the aforementioned arrangement.

It would be further advantageous to provide for the effective interconnection of the sub components of a camera system.

SUMMARY OF THE INVENTION

According to a first aspect of the invention, there is provided a printhead assembly for a camera system having a chassis and a platen assembly that is mountable on the chassis, the platen assembly being configured to support passage of a print medium along a printing path, the printhead assembly comprising

an ink reservoir assembly that is mountable on the chassis and defines at least three ink reservoirs in which differently colored inks are received, the ink reservoir assembly defining an outlet;

a guide assembly that is positioned in the ink reservoir assembly to define at least three discrete ink paths that open at the outlet; and

at least one printhead integrated circuit that is positioned in the outlet to span the printing path, the, or each, printhead integrated circuit defining at least three sets of inlet apertures, each set of inlet apertures being aligned with a respective ink path.

The ink reservoir assembly may define three ink reservoirs and the guide assembly may define three discrete ink paths.

Both the ink reservoir assembly and the guide assembly may be elongate to span the printing path. The ink reservoir assembly may include an elongate base member and an elongate cover member, the cover member having a roof wall, a pair of opposed side walls and a pair of spaced inner walls, the side walls and the inner walls depending from the roof wall and being generally parallel to each other and the base member having a floor and a pair of opposed end walls and defining an elongate opening in which the printhead integrated circuits are mounted, the guide assembly being interposed between lower ends of the inner walls and the floor.

The guide assembly may include a pair of guide walls that extend from respective lower ends of the inner walls inwardly towards the elongate opening to define the three distinct ink paths that terminate at respective sets of inlet apertures of the printhead integrated circuits.

The base member, the cover member and the guide assembly may be molded of a plastics material.

One of the end walls may define a number of air inlet openings that are treated to be hydrophobic to permit the ingress of air into the ink reservoirs as ink is fed from the ink reservoirs and to inhibit the egress of ink.

A sponge-like member may be positioned in each ink reservoir to store the ink while inhibiting agitation of ink during general use of the camera system.

The invention extends to a camera system that includes a printhead assembly as described above.

In accordance with a second aspect of the present invention, there is provided in a camera system comprising: an image sensor device for sensing an image; a processing means for processing the sensed image; a print media supply means for the supply of print media to a print head; a print head for printing the sensed image on the print media stored internally to the camera system; a portable power supply interconnected to the print head, the sensor and the processing means; and a guillotine mechanism located between the print media supply means and the print head and adapted to cut the print media into sheets of a predetermined size.

Further, preferably, the guillotine mechanism is detachable from the camera system. The guillotine mechanism can be attached to the print media supply means and is detachable from the camera system with the print media supply means. The guillotine mechanism can be mounted on a platen unit below the print head.

BRIEF DESCRIPTION OF THE DRAWINGS

Notwithstanding any other forms which may fall within the scope of the present invention, preferred forms of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

FIG. 1 illustrates a front perspective view of the assembled camera of the preferred embodiment;

FIG. 2 illustrates a rear perspective view, partly exploded, of the preferred embodiment;

FIG. 3 is a perspective view of the chassis of the preferred embodiment;

FIG. 4 is a perspective view of the chassis illustrating mounting of electric motors;

FIG. 5 is an exploded perspective of the ink supply mechanism of the preferred embodiment;

FIG. 6 is rear perspective of the assembled form of the ink supply mechanism of the preferred embodiment;

FIG. 7 is a front perspective view of the assembled form of the ink supply mechanism of the preferred embodiment;

FIG. 8 is an exploded perspective view of the platen unit of the preferred embodiment;

FIG. 9 is a perspective view of the assembled form of the platen unit;

FIG. 10 is also a perspective view of the assembled form of the platen unit;

FIG. 11 is an exploded perspective view of the printhead recapping mechanism of the preferred embodiment;

FIG. 12 is a close up exploded perspective of the recapping mechanism of the preferred embodiment;

FIG. 13 is an exploded perspective of the ink supply cartridge of the preferred embodiment;

FIG. 14 is a close up perspective, view partly in section, of the internal portions of the ink supply cartridge in an assembled form;

FIG. 15 is a schematic block diagram of one form of integrated circuit layer of the image capture and processing integrated circuit of the preferred embodiment;

FIG. 16 is an exploded view perspective illustrating the assembly process of the preferred embodiment;

FIG. 17 illustrates a front exploded perspective view of the assembly process of the preferred embodiment;

FIG. 18 illustrates a perspective view of the assembly process of the preferred embodiment;

FIG. 19 illustrates a perspective view of the assembly process of the preferred embodiment;

FIG. 20 is a perspective view illustrating the insertion of the platen unit in the preferred embodiment;

FIG. 21 illustrates the interconnection of the electrical components of the preferred embodiment;

FIG. 22 illustrates the process of assembling the preferred embodiment; and

FIG. 23 is a perspective view further illustrating the assembly process of the preferred embodiment.

DESCRIPTION OF PREFERRED AND OTHER EMBODIMENTS

Turning initially simultaneously to FIG. 1 and FIG. 2 there are illustrated perspective views of an assembled camera constructed in accordance with the preferred embodiment with FIG. 1 showing a front perspective view and FIG. 2 showing a rear perspective view. The camera 1 includes a paper or plastic film jacket 2 which can include simplified instructions 3 for the operation of the camera system 1. The camera system 1 includes a first “take” button 4 which is depressed to capture an image. The captured image is output via output slot 6. A further copy of the image can be obtained through depressing a second “printer copy” button 7 whilst an LED light 5 is illuminated. The camera system also provides the usual view finder 8 in addition to a CCD image capture/lensing system 9.

The camera system 1 provides for a standard number of output prints after which the camera system 1 ceases to function. A prints left indicator slot 10 is provided to indicate the number of remaining prints. A refund scheme at the point of purchase is assumed to be operational for the return of used camera systems for recycling.

Turning now to FIG. 3, the assembly of the camera system is based around an internal chassis 12 which can be a plastic injection molded part. A pair of paper pinch rollers 28, 29 utilized for decurling are snap fitted into corresponding frame holes eg. 26, 27.

As shown in FIG. 4, the chassis 12 includes a series of mutually opposed prongs eg. 13, 14 into which is snapped fitted a series of electric motors 16, 17. The electric motors 16, 17 can be entirely standard with the motor 16 being of a stepper motor type. The motor 16, 17 include cogs 19, 20 for driving a series of gear wheels. A first set of gear wheels is provided for controlling a paper cutter mechanism and a second set is provided for controlling print roll movement.

Turning next to FIGS. 5 to 7, there is illustrated an ink supply mechanism 40 utilized in the camera system. FIG. 5 illustrates a back exploded perspective view, FIG. 6 illustrates a back assembled view and FIG. 7 illustrates a front assembled view. The ink supply mechanism 40 is based around an ink supply cartridge 42 which contains printer ink and a print head mechanism for printing out pictures on demand. The ink supply cartridge 42 includes a side aluminium strip 43 which is provided as a shear strip to assist in cutting images from a paper roll.

A dial mechanism 44 is provided for indicating the number of “prints left”. The dial mechanism 44 is snap fitted through a corresponding mating portion 46 so as to be freely rotatable.

As shown in FIG. 6, the mechanism 40 includes a flexible PCB strip 47 which interconnects with the print head and provides for control of the print head. The interconnection between the Flex PCB strip and an image sensor and print head integrated circuit can be via Tape Automated Bonding (TAB) Strips 51, 58. A moulded aspherical lens and aperture shim 50 (FIG. 5) is also provided for imaging an image onto the surface of the image sensor integrated circuit normally located within cavity 53 and a light box module or hood 52 is provided for snap fitting over the cavity 53 so as to provide for proper light control. A series of decoupling capacitors eg. 34 can also be provided. Further a plug 45 (FIG. 7) is provided for re-plugging ink holes after refilling. A series of guide prongs eg. 55-57 are further provided for guiding the flexible PCB strip 47.

The ink supply mechanism 40 interacts with a platen unit 60 which guides print media under a printhead located in the ink supply mechanism. FIG. 8 shows an exploded view of the platen unit 60, while FIGS. 9 and 10 show assembled views of the platen unit. The platen unit 60 includes a first pinch roller 61 which is snap fitted to one side of a platen base 62. Attached to a second side of the platen base 62 is a cutting mechanism 63 which traverses the platen unit 60 by means of a rod 64 having a screw thread which is rotated by means of cogged wheel 65 which is also fitted to the platen base 62. The screw threaded rod 64 mounts a block 67 which includes a cutting wheel 68 fastened via a fastener 69. Also mounted to the block 67 is a counter actuator which includes a pawl 71. The pawl 71 acts to rotate the dial mechanism 44 of FIG. 6 upon the return traversal of the cutting wheel. As shown previously in FIG. 6, the dial mechanism 44 includes a cogged surface which interacts with pawl 71, thereby maintaining a count of the number of photographs by means of numbers embossed on the surface of dial mechanism 44. The cutting mechanism 63 is inserted into the platen base 62 by means of a snap fit via clips 74.

The platen unit 60 includes an internal recapping mechanism 80 for recapping the print head when not in use. The recapping mechanism 80 includes a sponge portion 81 and is operated via a solenoid coil so as to provide for recapping of the print head. In the preferred embodiment, there is provided an inexpensive form of printhead re-capping mechanism provided for incorporation into a handheld camera system so as to provide for printhead re-capping of an inkjet printhead.

FIG. 11 illustrates an exploded view of the recapping mechanism whilst FIG. 12 illustrates a close up of the end portion thereof. The re-capping mechanism 80 is structured around a solenoid including a 16 turn coil 75 which can comprise insulated wire. The coil 75 is turned around a first stationery solenoid arm 76 which is mounted on a bottom surface of the platen base 62 (FIG. 8) and includes a post portion 77 to magnify effectiveness of operation. The arm 76 can comprise a ferrous material.

A second moveable arm 78 of the solenoid actuator is also provided. The arm 78 is moveable and is also made of ferrous material. Mounted on the arm is a sponge portion surrounded by an elastomer strip 79. The elastomer strip 79 is of a generally arcuate cross-section and act as a leaf spring against the surface of the printhead ink supply cartridge 42 (FIG. 5) so as to provide for a seal against the surface of the printhead ink supply cartridge 42. In the quiescent position an elastomer spring unit 87, 88 acts to resiliently deform the elastomer seal 79 against the surface of the ink supply unit 42.

When it is desired to operate the printhead unit, upon the insertion of paper, the solenoid coil 75 is activated so as to cause the arm 78 to move down to be adjacent to the end plate 76. The arm 78 is held against end plate 76 while the printhead is printing by means of a small “keeper current” in coil 75. Simulation results indicate that the keeper current can be significantly less than the actuation current. Subsequently, after photo printing, the paper is guillotined by the cutting mechanism 63 of FIG. 8 acting against Aluminium Strip 43, and rewound so as to clear the area of the re-capping mechanism 80. Subsequently, the current is turned off and springs 87, 88 return the arm 78 so that the elastomer seal is again resting against the printhead ink supply cartridge.

It can be seen that the preferred embodiment provides for a simple and inexpensive means of re-capping a printhead through the utilisation of a solenoid type device having a long rectangular form. Further, the preferred embodiment utilises minimal power in that currents are only required whilst the device is operational and additionally, only a low keeper current is required whilst the printhead is printing.

Turning next to FIGS. 13 and 14, FIG. 13 illustrates an exploded perspective of the ink supply cartridge 42 whilst FIG. 14 illustrates a close up sectional view of a bottom of the ink supply cartridge with the printhead unit in place. The ink supply cartridge 42 is based around a pagewidth printhead 102 which comprises a long slither of silicon having a series of holes etched on the back surface for the supply of ink to a front surface of the silicon wafer for subsequent ejection via a micro electro mechanical system. The form of ejection can be many different forms such as those set out in the tables below.

Of course, many other inkjet technologies, as referred to the attached tables below, can also be utilised when constructing a printhead unit 102. The fundamental requirement of the ink supply cartridge 42 is the supply of ink to a series of colour channels etched through the back surface of the printhead 102. In the description of the preferred embodiment, it is assumed that a three colour printing process is to be utilised so as to provide full colour picture output. Hence, the print supply unit includes three ink supply reservoirs being a cyan reservoir 104, a magenta reservoir 105 and a yellow reservoir 106. Each of these reservoirs is required to store ink and includes a corresponding sponge type material 107-109 which assists in stabilising ink within the corresponding ink channel and inhibiting the ink from sloshing back and forth when the printhead is utilised in a handheld camera system. The reservoirs 104, 105, 106 are formed through the mating of first exterior plastic piece 110 and a second base piece 111.

At a first end 118 of the base piece 111 a series of air inlet 113-115 are provided. Each air inlet leads to a corresponding winding channel which is hydrophobically treated so as to act as an ink repellent and therefore repel any ink that may flow along the air inlet channel. The air inlet channel further takes a convoluted path assisting in resisting any ink flow out of the chambers 104-106. An adhesive tape portion 117 is provided for sealing the channels within end portion 118.

At the top end, there is included a series of refill holes (not shown) for refilling corresponding ink supply chambers 104, 105, 106. A plug 121 is provided for sealing the refill holes.

Turning now to FIG. 14, there is illustrated a close up perspective view, partly in section through the ink supply cartridge 42 of FIG. 13 when formed as a unit. The ink supply cartridge includes the three colour ink reservoirs 104, 105, 106 which supply ink to different portions of the back surface of printhead 102 which includes a series of apertures 128 defined therein for carriage of the ink to the front surface.

The ink supply cartridge 42 includes two guide walls 124, 125 which separate the various ink chambers and are tapered into an end portion abutting the surface of the printhead 102. The guide walls 124, 125 are further mechanically supported by block portions eg. 126 which are placed at regular intervals along the length of the ink supply unit. The block portions 126 leave space at portions close to the back of printhead 102 for the flow of ink around the back surface thereof.

The ink supply unit is preferably formed from a multi-part plastic injection mould and the mould pieces eg. 110, 111 (FIG. 13) snap together around the sponge pieces 107, 109. Subsequently, a syringe type device can be inserted in the ink refill holes and the ink reservoirs filled with ink with the air flowing out of the air outlets 113-115. Subsequently, the adhesive tape portion 117 and plug 121 are attached and the printhead tested for operation capabilities. Subsequently, the ink supply cartridge 42 can be readily removed for refilling by means of removing the ink supply cartridge, performing a washing cycle, and then utilising the holes for the insertion of a refill syringe filled with ink for refilling the ink chamber before returning the ink supply cartridge 42 to a camera.

Turning now to FIG. 15, there is shown an example layout of the Image Capture and Processing integrated circuit (ICP) 48.

The Image Capture and Processing integrated circuit 48 provides most of the electronic functionality of the camera with the exception of the print head integrated circuit. The integrated circuit 48 is a highly integrated system. It combines CMOS image sensing, analog to digital conversion, digital image processing, DRAM storage, ROM, and miscellaneous control functions in a single integrated circuit.

The integrated circuit is estimated to be around 32 mm² using a leading edge 0.18 micron CMOS/DRAM/APS process. The integrated circuit size and cost can scale somewhat with Moore's law, but is dominated by a CMOS active pixel sensor array 201, so scaling is limited as the sensor pixels approach the diffraction limit.

The ICP 48 includes CMOS logic, a CMOS image sensor, DRAM, and analog circuitry. A very small amount of flash memory or other non-volatile memory is also preferably included for protection against reverse engineering.

Alternatively, the ICP can readily be divided into two integrated circuits: one for the CMOS imaging array, and the other for the remaining circuitry. The cost of this two integrated circuit solution should not be significantly different than the single integrated circuit ICP, as the extra cost of packaging and bond-pad area is somewhat cancelled by the reduced total wafer area requiring the color filter fabrication steps.

The ICP preferably contains the following functions: Function 1.5 megapixel image sensor Analog Signal Processors Image sensor column decoders Image sensor row decoders Analogue to Digital Conversion (ADC) Column ADC's Auto exposure 12 Mbits of DRAM DRAM Address Generator Color interpolator Convolver Color ALU Halftone matrix ROM Digital halftoning Print head interface 8 bit CPU core Program ROM Flash memory Scratchpad SRAM Parallel interface (8 bit) Motor drive transistors (5) Clock PLL JTAG test interface Test circuits Busses Bond pads

The CPU, DRAM, Image sensor, ROM, Flash memory, Parallel interface, JTAG interface and ADC can be vendor supplied cores. The ICP is intended to run on 1.5V to minimize power consumption and allow convenient operation from two AA type battery cells.

FIG. 15 illustrates a layout of the ICP 48. The ICP 48 is dominated by the imaging array 201, which consumes around 80% of the integrated circuit area. The imaging array is a CMOS 4 transistor active pixel design with a resolution of 1,500×1,000. The array can be divided into the conventional configuration, with two green pixels, one red pixel, and one blue pixel in each pixel group. There are 750×500 pixel groups in the imaging array.

The latest advances in the field of image sensing and CMOS image sensing in particular can be found in the October, 1997 issue of IEEE Transactions on Electron Devices and, in particular, pages 1689 to 1968. Further, a specific implementation similar to that disclosed in the present application is disclosed in Wong et. al, “CMOS Active Pixel Image Sensors Fabricated Using a 1.8V, 0.25 μm CMOS Technology”, IEDM 1996, page 915

The imaging array uses a 4 transistor active pixel design of a standard configuration. To minimize integrated circuit area and therefore cost, the image sensor pixels should be as small as feasible with the technology available. With a four transistor cell, the typical pixel size scales as 20 times the lithographic feature size. This allows a minimum pixel area of around 3.6 μm×3.6 μm. However, the photosite must be substantially above the diffraction limit of the lens. It is also advantageous to have a square photosite, to maximize the margin over the diffraction limit in both horizontal and vertical directions. In this case, the photosite can be specified as 2.5 μm×2.5 μm. The photosite can be a photogate, pinned photodiode, charge modulation device, or other sensor.

The four transistors are packed as an ‘L’ shape, rather than a rectangular region, to allow both the pixel and the photosite to be square. This reduces the transistor packing density slightly, increasing pixel size. However, the advantage in avoiding the diffraction limit is greater than the small decrease in packing density.

The transistors also have a gate length which is longer than the minimum for the process technology. These have been increased from a drawn length of 0.18 micron to a drawn length of 0.36 micron. This is to improve the transistor matching by making the variations in gate length represent a smaller proportion of the total gate length.

The extra gate length, and the ‘L’ shaped packing, mean that the transistors use more area than the minimum for the technology. Normally, around 8 μm² would be required for rectangular packing. Preferably, 9.75 μm² has been allowed for the transistors.

The total area for each pixel is 16 μm², resulting from a pixel size of 4 μm×4 μm. With a resolution of 1,500×1,000, the area of the imaging array 101 is 6,000 μm×4,000 μm, or 24 mm².

The presence of a color image sensor on the integrated circuit affects the process required in two major ways:

The CMOS fabrication process should be optimized to minimize dark current

Color filters are required. These can be fabricated using dyed photosensitive polyimides, resulting in an added process complexity of three spin coatings, three photolithographic steps, three development steps, and three hardbakes.

There are 15,000 analog signal processors (ASPs) 205, one for each of the columns of the sensor. The ASPs amplify the signal, provide a dark current reference, sample and hold the signal, and suppress the fixed pattern noise (FPN).

There are 375 analog to digital converters 206, one for each four columns of the sensor array. These may be delta-sigma or successive approximation type ADC's. A row of low column ADC's are used to reduce the conversion speed required, and the amount of analog signal degradation incurred before the signal is converted to digital. This also eliminates the hot spot (affecting local dark current) and the substrate coupled noise that would occur if a single high speed ADC was used. Each ADC also has two four bit DAC's which trim the offset and scale of the ADC to further reduce FPN variations between columns. These DAC's are controlled by data stored in flash memory during integrated circuit testing.

The column select logic 204 is a 1:1500 decoder which enables the appropriate digital output of the ADCs onto the output bus. As each ADC is shared by four columns, the least significant two bits of the row select control 4 input analog multiplexors.

A row decoder 207 is a 1:1000 decoder which enables the appropriate row of the active pixel sensor array. This selects which of the 1000 rows of the imaging array is connected to analog signal processors. As the rows are always accessed in sequence, the row select logic can be implemented as a shift register.

An auto exposure system 208 adjusts the reference voltage of the ADC 205 in response to the maximum intensity sensed during the previous frame period. Data from the green pixels is passed through a digital peak detector. The peak value of the image frame period before capture (the reference frame) is provided to a digital to analogue converter (DAC), which generates the global reference voltage for the column ADCs. The peak detector is reset at the beginning of the reference frame. The minimum and maximum values of the three RGB color components are also collected for color correction.

The second largest section of the integrated circuit is consumed by a DRAM 210 used to hold the image. To store the 1,500×1,000 image from the sensor without compression, 1.5 Mbytes of DRAM 210 are required. This equals 12 Mbits, or slightly less than 5% of a 256 Mbit DRAM. The DRAM technology assumed is of the 256 Mbit generation implemented using 0.18 μm CMOS.

Using a standard 8F cell, the area taken by the memory array is 3.11 mm². When row decoders, column sensors, redundancy, and other factors are taken into account, the DRAM requires around 4 mm².

This DRAM 210 can be mostly eliminated if analog storage of the image signal can be accurately maintained in the CMOS imaging array for the two seconds required to print the photo. However, digital storage of the image is preferable as it is maintained without degradation, is insensitive to noise, and allows copies of the photo to be printed considerably later.

A DRAM address generator 211 provides the write and read addresses to the DRAM 210. Under normal operation, the write address is determined by the order of the data read from the CMOS image sensor 201. This will typically be a simple raster format. However, the data can be read from the sensor 201 in any order, if matching write addresses to the DRAM are generated. The read order from the DRAM 210 will normally simply match the requirements of a color interpolator and the print head. As the cyan, magenta, and yellow rows of the print head are necessarily offset by a few pixels to allow space for nozzle actuators, the colors are not read from the DRAM simultaneously. However, there is plenty of time to read all of the data from the DRAM many times during the printing process. This capability is used to eliminate the need for FIFOs in the print head interface, thereby saving integrated circuit area. All three RGB image components can be read from the DRAM each time color data is required. This allows a color space converter to provide a more sophisticated conversion than a simple linear RGB to CMY conversion.

Also, to allow two dimensional filtering of the image data without requiring line buffers, data is re-read from the DRAM array.

The address generator may also implement image effects in certain models of camera. For example, passport photos are generated by a manipulation of the read addresses to the DRAM. Also, image framing effects (where the central image is reduced), image warps, and kaleidoscopic effects can all be generated by manipulating the read addresses of the DRAM.

While the address generator 211 may be implemented with substantial complexity if effects are built into the standard integrated circuit, the integrated circuit area required for the address generator is small, as it consists only of address counters and a moderate amount of random logic.

A color interpolator 214 converts the interleaved pattern of red, 2× green, and blue pixels into RGB pixels. It consists of three 8 bit adders and associated registers. The divisions are by either 2 (for green) or 4 (for red and blue) so they can be implemented as fixed shifts in the output connections of the adders.

A convolver 215 is provided as a sharpening filter which applies a small convolution kernel (5×5) to the red, green, and blue planes of the image. The convolution kernel for the green plane is different from that of the red and blue planes, as green has twice as many samples. The sharpening filter has five functions:

To improve the color interpolation from the linear interpolation provided by the color interpolator, to a close approximation of a sinc interpolation.

To compensate for the image ‘softening’ which occurs during digitization.

To adjust the image sharpness to match average consumer preferences, which are typically for the image to be slightly sharper than reality. As the single use camera is intended as a consumer product, and not a professional photographic products, the processing can match the most popular settings, rather than the most accurate.

To suppress the sharpening of high frequency (individual pixel) noise. The function is similar to the ‘unsharp mask’ process.

To antialias Image Warping.

These functions are all combined into a single convolution matrix. As the pixel rate is low (less than 1 Mpixel per second) the total number of multiplies required for the three color channels is 56 million multiplies per second. This can be provided by a single multiplier. Fifty bytes of coefficient ROM are also required.

A color ALU 113 combines the functions of color compensation and color space conversion into the one matrix multiplication, which is applied to every pixel of the frame. As with sharpening, the color correction should match the most popular settings, rather than the most accurate.

A color compensation circuit of the color ALU provides compensation for the lighting of the photo. The vast majority of photographs are substantially improved by a simple color compensation, which independently normalizes the contrast and brightness of the three color components.

A color look-up table (CLUT) 212 is provided for each color component. These are three separate 256×8 SRAMs, requiring a total of 6,144 bits. The CLUTs are used as part of the color correction process. They are also used for color special effects, such as stochastically selected “wild color” effects.

A color space conversion system of the color ALU converts from the RGB color space of the image sensor to the CMY color space of the printer. The simplest conversion is a 1's complement of the RGB data. However, this simple conversion assumes perfect linearity of both color spaces, and perfect dye spectra for both the color filters of the image sensor, and the ink dyes. At the other extreme is a tri-linear interpolation of a sampled three dimensional arbitrary transform table. This can effectively match any non-linearity or differences in either color space. Such a system is usually necessary to obtain good color space conversion when the print engine is a color electrophotographic

However, since the non-linearity of a halftoned ink jet output is very small, a simpler system can be used. A simple matrix multiply can provide excellent results. This requires nine multiplies and six additions per contone pixel. However, since the contone pixel rate is low (less than 1 Mpixel/sec) these operations can share a single multiplier and adder. The multiplier and adder are used in a color ALU which is shared with the color compensation function.

Digital halftoning can be performed as a dispersed dot ordered dither using a stochastic optimized dither cell. A halftone matrix ROM 216 is provided for storing dither cell coefficients. A dither cell size of 32×32 is adequate to ensure that the cell repeat cycle is not visible. The three colors—cyan, magenta, and yellow—are all dithered using the same cell, to ensure maximum co-positioning of the ink dots. This minimizes ‘muddying’ of the mid-tones which results from bleed of dyes from one dot to adjacent dots while still wet. The total ROM size required is 1 KByte, as the one ROM is shared by the halftoning units for each of the three colors.

The digital halftoning used is dispersed dot ordered dither with stochastic optimized dither matrix. While dithering does not produce an image quite as ‘sharp’ as error diffusion, it does produce a more accurate image with fewer artifacts. The image sharpening produced by error diffusion is artificial, and less controllable and accurate than ‘unsharp mask’ filtering performed in the contone domain. The high print resolution (1,600 dpi×1,600 dpi) results in excellent quality when using a well formed stochastic dither matrix.

Digital halftoning is performed by a digital halftoning unit 217 using a simple comparison between the contone information from the DRAM 210 and the contents of the dither matrix 216. During the halftone process, the resolution of the image is changed from the 250 dpi of the captured contone image to the 1,600 dpi of the printed image. Each contone pixel is converted to an average of 40.96 halftone dots.

The ICP incorporates a 16 bit microcontroller CPU core 219 to run the miscellaneous camera functions, such as reading the buttons, controlling the motor and solenoids, setting up the hardware, and authenticating the refill station. The processing power required by the CPU is very modest, and a wide variety of processor cores can be used. As the entire CPU program is run from a small ROM 220[.], program compatibility between camera versions is not important, as no external programs are run. A 2 Mbit (256 Kbyte) program and data ROM 220 is included on integrated circuit. Most of this ROM space is allocated to data for outline graphics and fonts for specialty cameras. The program requirements are minor. The single most complex task is the encrypted authentication of the refill station. The ROM requires a single transistor per bit.

A Flash memory 221 may be used to store a 128 bit authentication code. This provides higher security than storage of the authentication code in ROM, as reverse engineering can be made essentially impossible. The Flash memory is completely covered by third level metal, making the data impossible to extract using scanning probe microscopes or electron beams. The authentication code is stored in the integrated circuit when manufactured. At least two other Flash bits are required for the authentication process: a bit which locks out reprogramming of the authentication code, and a bit which indicates that the camera has been refilled by an authenticated refill station. The flash memory can also be used to store FPN correction data for the imaging array. Additionally, a phase locked loop rescaling parameter is stored for scaling the clocking cycle to an appropriate correct time. The clock frequency does not require crystal accuracy since no date functions are provided. To eliminate the cost of a crystal, an on integrated circuit oscillator with a phase locked loop 224 is used. As the frequency of an on-integrated circuit oscillator is highly variable from integrated circuit to integrated circuit, the frequency ratio of the oscillator to the PLL is digitally trimmed during initial testing. The value is stored in Flash memory 221. This allows the clock PLL to control the ink-jet heater pulse width with sufficient accuracy.

A scratchpad SRAM is a small static RAM 222 with a 6T cell. The scratchpad provided temporary memory for the 16 bit CPU. 1024 bytes is adequate.

A print head interface 223 formats the data correctly for the print head. The print head interface also provides all of the timing signals required by the print head. These timing signals may vary depending upon temperature, the number of dots printed simultaneously, the print medium in the print roll, and the dye density of the ink in the print roll.

The following is a table of external connections to the print head interface: Connection Function Pins DataBits[0-7] Independent serial data to the eight segments 8 of the print head BitClock Main data clock for the print head 1 ColorEnable[0-2] Independent enable signals for the CMY 3 actuators, allowing different pulse times for each color. BankEnable[0-1] Allows either simultaneous or interleaved 2 actuation of two banks of nozzles. This allows two different print speed/power consumption tradeoffs NozzleSelect[0-4] Selects one of 32 banks of nozzles for simultaneous actuation 5 ParallelXferClock Loads the parallel transfer register with the 1 data from the shift registers Total 20

The print head utilized is composed of eight identical segments, each 1.25 cm long. There is no connection between the segments on the print head integrated circuit. Any connections required are made in the external TAB bonding film, which is double sided. The division into eight identical segments is to simplify lithography using wafer steppers. The segment width of 1.25 cm fits easily into a stepper field. As the print head integrated circuit is long and narrow (10 cm×0.3 mm), the stepper field contains a single segment of 32 print head integrated circuits. The stepper field is therefore 1.25 cm×1.6 cm. An average of four complete print heads are patterned in each wafer step.

A single BitClock output line connects to all 8 segments on the print head. The 8 DataBits lines lead one to each segment, and are clocked into the 8 segments on the print head simultaneously (on a BitClock pulse). For example, dot 0 is transferred to segment₀, dot 750 is transferred to segment₁, dot 1500 to segment₂ etc simultaneously.

The ParallelXferClock is connected to each of the 8 segments on the print head, so that on a single pulse, all segments transfer their bits at the same time.

The NozzleSelect, BankEnable and ColorEnable lines are connected to each of the 8 segments, allowing the print head interface to independently control the duration of the cyan, magenta, and yellow nozzle energizing pulses. Registers in the Print Head Interface allow the accurate specification of the pulse duration between 0 and 6 ms, with a typical duration of 2 ms to 3 ms.

A parallel interface 125 connects the ICP to individual static electrical signals. The CPU is able to control each of these connections as memory mapped I/O via a low speed bus.

The following is a table of connections to the parallel interface: Connection Direction Pins Paper transport stepper motor Output 4 Capping solenoid Output 1 Copy LED Output 1 Photo button Input 1 Copy button Input 1 Total 8

Seven high current drive transistors eg. 227 are required. Four are for the four phases of the main stepper motor, two are for the guillotine motor, and the remaining transistor is to drive the capping solenoid. These transistors are allocated 20,000 square microns (600,000 F) each. As the transistors are driving highly inductive loads, they must either be turned off slowly, or be provided with a high level of back EMF protection. If adequate back EMF protection cannot be provided using the integrated circuit process chosen, then external discrete transistors should be used. The transistors are never driven at the same time as the image sensor is used. This is to avoid voltage fluctuations and hot spots affecting the image quality. Further, the transistors are located as far away from the sensor as possible.

A standard JTAG (Joint Test Action Group) interface 228 is included in the ICP for testing purposes and for interrogation by the refill station. Due to the complexity of the integrated circuit, a variety of testing techniques are required, including BIST (Built In Self Test) and functional block isolation. An overhead of 10% in integrated circuit area is assumed for integrated circuit testing circuitry for the random logic portions. The overhead for the large arrays the image sensor and the DRAM is smaller.

The JTAG interface is also used for authentication of the refill station. This is included to ensure that the cameras are only refilled with quality paper and ink at a properly constructed refill station, thus preventing inferior quality refills from occurring. The camera must authenticate the refill station, rather than vice versa. The secure protocol is communicated to the refill station during the automated test procedure. Contact is made to four gold plated spots on the ICP/print head TAB by the refill station as the new ink is injected into the print head.

FIG. 16 illustrates a rear view of the next step in the construction process whilst FIG. 17 illustrates a front view.

Turning now to FIG. 16, the assembly of the camera system proceeds via first assembling the ink supply mechanism 40. The flex PCB is interconnected with batteries 84 only one of which is shown, which are inserted in the middle portion of a print roll 85 which is wrapped around a plastic former 86. An end cap 89 is provided at the other end of the print roll 85 so as to fasten the print roll and batteries firmly to the ink supply mechanism.

The solenoid coil is interconnected (not shown) to interconnects 97, 98 (FIG. 8) which include leaf spring ends for interconnection with electrical contacts on the Flex PCB so as to provide for electrical control of the solenoid.

Turning now to FIGS. 17-19 the next step in the construction process is the insertion of the relevant gear trains into the side of the camera chassis. FIG. 17 illustrates a front view, FIG. 18 illustrates a rear view and FIG. 19 also illustrates a rear view. The first gear train comprising gear wheels 22, 23 is utilised for driving the guillotine blade with the gear wheel 23 engaging the gear wheel 65 of FIG. 8. The second gear train comprising gear wheels 24, 25 and 26 engage one end of the print roller 61 of FIG. 8. As best indicated in FIG. 18, the gear wheels mate with corresponding pins on the surface of the chassis with the gear wheel 26 being snap fitted into corresponding mating hole 27.

Next, as illustrated in FIG. 20, the assembled platen unit 60 is then inserted between the print roll 85 and aluminium cutting blade 43.

Turning now to FIG. 21, by way of illumination, there is illustrated the electrically interactive components of the camera system. As noted previously, the components are based around a Flex PCB board and include a TAB film 58 which interconnects the printhead 102 with the image sensor and processing integrated circuit 48. Power is supplied by two AA type batteries 83, 84 and a paper drive stepper motor 16 is provided in addition to a rotary guillotine motor 17.

An optical element 31 is provided for snapping into a top portion of the chassis 12. The optical element 31 includes portions defining an optical view finder 32, 33 which are slotted into mating portions 35, 36 in view finder channel 37. Also provided in the optical element 31 is a lensing system 38 for magnification of the prints left number in addition to an optical pipe element 39 for piping light from the LED 5 for external display.

Turning next to FIG. 22, the assembled unit 90 is then inserted into a front outer case 91 which includes button 4 for activation of printouts.

Turning now to FIG. 23, next, the unit 90 is provided with a snap-on back cover 93 which includes a slot 6 and copy print button 7. A wrapper label containing instructions and advertising (not shown) is then wrapped around the outer surface of the camera system and pinch clamped to the cover by means of clamp strip 96 which can comprise a flexible plastic or rubber strip.

Subsequently, the preferred embodiment is ready for use as a one time use camera system that provides for instant output images on demand. It will be evident that the preferred embodiment further provides for a refillable camera system. A used camera can be collected and its outer plastic cases removed and recycled. A new paper roll and batteries can be added and the ink cartridge refilled. A series of automatic test routines can then be carried out to ensure that the printer is properly operational. Further, in order to ensure only authorised refills are conducted so as to enhance quality, routines in the on-integrated circuit program ROM can be executed such that the camera authenticates the refilling station using a secure protocol. Upon authentication, the camera can reset an internal paper count and an external case can be fitted on the camera system with a new outer label. Subsequent packing and shipping can then take place.

It will be further readily evident to those skilled in the art that the program ROM can be modified so as to allow for a variety of digital processing routines. In addition to the digitally enhanced photographs optimised for mainstream consumer preferences, various other models can readily be provided through mere re-programming of the program ROM. For example, a sepia classic old fashion style output can be provided through a remapping of the colour mapping function. A further alternative is to provide for black and white outputs again through a suitable colour remapping algorithm. Minimum colour can also be provided to add a touch of colour to black and white prints to produce the effect that was traditionally used to colourize black and white photos. Further, passport photo output can be provided through suitable address remappings within the address generators. Further, edge filters can be utilised as is known in the field of image processing to produce sketched art styles. Further, classic wedding borders and designs can be placed around an output image in addition to the provision of relevant clip arts. For example, a wedding style camera might be provided. Further, a panoramic mode can be provided so as to output the well known panoramic format of images. Further, a postcard style output can be provided through the printing of postcards including postage on the back of a print roll surface. Further, cliparts can be provided for special events such as Halloween, Christmas etc. Further, kaleidoscopic effects can be provided through address remappings and wild colour effects can be provided through remapping of the colour lookup table. Many other forms of special event cameras can be provided for example, cameras dedicated to the Olympics, movie tie-ins, advertising and other special events.

The operational mode of the camera can be programmed so that upon the depressing of the take photo a first image is sampled by the sensor array to determine irrelevant parameters. Next a second image is again captured which is utilised for the output. The captured image is then manipulated in accordance with any special requirements before being initially output on the paper roll. The LED light is then activated for a predetermined time during which the DRAM is refreshed so as to retain the image. If the print copy button is depressed during this predetermined time interval, a further copy of the photo is output. After the predetermined time interval where no use of the camera has occurred, the onboard CPU shuts down all power to the camera system until such time as the take button is again activated. In this way, substantial power savings can be realized.

Ink Jet Technologies

The embodiments of the invention use an inkjet printer type device. Of course many different devices could be used. However presently popular ink jet printing technologies are unlikely to be suitable.

The most significant problem with thermal inkjet is power consumption. This is approximately 100 times that required for high speed, and stems from the energy-inefficient means of drop ejection. This involves the rapid boiling of water to produce a vapor bubble which expels the ink. Water has a very high heat capacity, and must be superheated in thermal inkjet applications. This leads to an efficiency of around 0.02%, from electricity input to drop momentum (and increased surface area) out.

The most significant problem with piezoelectric inkjet is size and cost. Piezoelectric crystals have a very small deflection at reasonable drive voltages, and therefore require a large area for each nozzle. Also, each piezoelectric actuator must be connected to its drive circuit on a separate substrate. This is not a significant problem at the current limit of around 300 nozzles per print head, but is a major impediment to the fabrication of pagewide print heads with 19,200 nozzles.

Ideally, the inkjet technologies used meet the stringent requirements of in-camera digital color printing and other high quality, high speed, low cost printing applications. To meet the requirements of digital photography, new inkjet technologies have been created. The target features include:

low power (less than 10 Watts)

high resolution capability (1,600 dpi or more)

photographic quality output

low manufacturing cost

small size (pagewidth times minimum cross section)

high speed (<2 seconds per page).

All of these features can be met or exceeded by the inkjet systems described below with differing levels of difficulty. 45 different inkjet technologies have been developed by the Assignee to give a wide range of choices for high volume manufacture. These technologies form part of separate applications assigned to the present Assignee as set out in the table below.

The inkjet designs shown here are suitable for a wide range of digital printing systems, from battery powered one-time use digital cameras, through to desktop and network printers, and through to commercial printing systems

For ease of manufacture using standard process equipment, the print head is designed to be a monolithic 0.5 micron CMOS integrated circuit with MEMS post processing. For color photographic applications, the print head is 100 mm long, with a width which depends upon the inkjet type. The smallest print head designed is IJ38, which is 0.35 mm wide, giving a integrated circuit area of 35 square mm. The print heads each contain 19,200 nozzles plus data and control circuitry.

Ink is supplied to the back of the print head by injection molded plastic ink channels. The molding requires 50 micron features, which can be created using a lithographically micromachined insert in a standard injection molding tool. Ink flows through holes etched through the wafer to the nozzle chambers fabricated on the front surface of the wafer. The print head is connected to the camera circuitry by tape automated bonding.

Cross-Referenced Applications

The following table is a guide to cross-referenced patent applications filed concurrently herewith and discussed hereinafter with the reference being utilized in subsequent tables when referring to a particular case: Docket No. Reference Title IJ01US IJ01 Radiant Plunger Ink Jet Printer IJ02US IJ02 Electrostatic Ink Jet Printer IJ03US IJ03 Planar Thermoelastic Bend Actuator Ink Jet IJ04US IJ04 Stacked Electrostatic Ink Jet Printer IJ05US IJ05 Reverse Spring Lever Ink Jet Printer IJ06US IJ06 Paddle Type Ink Jet Printer IJ07US IJ07 Permanent Magnet Electromagnetic Ink Jet Printer IJ08US IJ08 Planar Swing Grill Electromagnetic Ink Jet Printer IJ09US IJ09 Pump Action Refill Ink Jet Printer IJ10US IJ10 Pulsed Magnetic Field Ink Jet Printer IJ11US IJ11 Two Plate Reverse Firing Electromagnetic Ink Jet Printer IJ12US IJ12 Linear Stepper Actuator Ink Jet Printer IJ13US IJ13 Gear Driven Shutter Ink Jet Printer IJ14US IJ14 Tapered Magnetic Pole Electromagnetic Ink Jet Printer IJ15US IJ15 Linear Spring Electromagnetic Grill Ink Jet Printer IJ16US IJ16 Lorenz Diaphragm Electromagnetic Ink Jet Printer IJ17US IJ17 PTFE Surface Shooting Shuttered Oscillating Pressure Ink Jet Printer IJ18US IJ18 Buckle Grip Oscillating Pressure Ink Jet Printer IJ19US IJ19 Shutter Based Ink Jet Printer IJ20US IJ20 Curling Calyx Thermoelastic Ink Jet Printer IJ21US IJ21 Thermal Actuated Ink Jet Printer IJ22US IJ22 Iris Motion Ink Jet Printer IJ23US IJ23 Direct Firing Thermal Bend Actuator Ink Jet Printer IJ24US IJ24 Conductive PTFE Ben Activator Vented Ink Jet Printer IJ25US IJ25 Magnetostrictive Ink Jet Printer IJ26US IJ26 Shape Memory Alloy Ink Jet Printer IJ27US IJ27 Buckle Plate Ink Jet Printer IJ28US IJ28 Thermal Elastic Rotary Impeller Ink Jet Printer IJ29US IJ29 Thermoelastic Bend Actuator Ink Jet Printer IJ30US IJ30 Thermoelastic Bend Actuator Using PTFE and Corrugated Copper Ink Jet Printer IJ31US IJ31 Bend Actuator Direct Ink Supply Ink Jet Printer IJ32US IJ32 A High Young's Modulus Thermoelastic Ink Jet Printer IJ33US IJ33 Thermally actuated slotted chamber wall ink jet printer IJ34US IJ34 Ink Jet Printer having a thermal actuator comprising an external coiled spring IJ35US IJ35 Trough Container Ink Jet Printer IJ36US IJ36 Dual Chamber Single Vertical Actuator Ink Jet IJ37US IJ37 Dual Nozzle Single Horizontal Fulcrum Actuator Ink Jet IJ38US IJ38 Dual Nozzle Single Horizontal Actuator Ink Jet IJ39US IJ39 A single bend actuator cupped paddle ink jet printing device IJ40US IJ40 A thermally actuated ink jet printer having a series of thermal actuator units IJ41US IJ41 A thermally actuated ink jet printer including a tapered heater element IJ42US IJ42 Radial Back-Curling Thermoelastic Ink Jet IJ43US IJ43 Inverted Radial Back-Curling Thermoelastic Ink Jet IJ44US IJ44 Surface bend actuator vented ink supply ink jet printer IJ45US IJ45 Coil Acutuated Magnetic Plate Ink Jet Printer

Tables of Drop-on-Demand Inkjets

Eleven important characteristics of the fundamental operation of individual inkjet nozzles have been identified. These characteristics are largely orthogonal, and so can be elucidated as an eleven dimensional matrix. Most of the eleven axes of this matrix include entries developed by the present assignee.

The following tables form the axes of an eleven dimensional table of inkjet types.

Actuator mechanism (18 types)

Basic operation mode (7 types)

Auxiliary mechanism (8 types)

Actuator amplification or modification method (17 types)

Actuator motion (19 types)

Nozzle refill method (4 types)

Method of restricting back-flow through inlet (10 types)

Nozzle clearing method (9 types)

Nozzle plate construction (9 types)

Drop ejection direction (5 types)

Ink type (7 types)

The complete eleven dimensional table represented by these axes contains 36.9 billion possible configurations of inkjet nozzle. While not all of the possible combinations result in a viable inkjet technology, many million configurations are viable. It is clearly impractical to elucidate all of the possible configurations. Instead, certain inkjet types have been investigated in detail. These are designated IJ01 to IJ45 above.

Other inkjet configurations can readily be derived from these 45 examples by substituting alternative configurations along one or more of the 11 axes. Most of the IJ01 to IJ45 examples can be made into inkjet print heads with characteristics superior to any currently available inkjet technology.

Where there are prior art examples known to the inventor, one or more of these examples are listed in the examples column of the tables below. The IJ01 to IJ45 series are also listed in the examples column. In some cases, a printer may be listed more than once in a table, where it shares characteristics with more than one entry.

Suitable applications include: Home printers, Office network printers, Short run digital printers, Commercial print systems, Fabric printers, Pocket printers, Internet WWW printers, Video printers, Medical imaging, Wide format printers, Notebook PC printers, Fax machines, Industrial printing systems, Photocopiers, Photographic minilabs etc.

The information associated with the aforementioned 11 dimensional matrix are set out in the following tables. ACTUATOR MECHANISM (APPLIED ONLY TO SELECTED INK DROPS) Actuator Mechanism Description Advantages Disadvantages Examples Thermal bubble An electrothermal heater heats the ink to 1) Large force generated 6) High power 16) Canon Bubblejet above boiling point, transferring 2) Simple construction 7) Ink carrier limited to water 1979 Endo et al GB significant heat to the aqueous ink. A 3) No moving parts 8) Low efficiency patent 2,007,162 bubble nucleates and quickly forms, 4) Fast operation 9) High temperatures required 17) Xerox heater-in- expelling the ink. 5) Small integrated circuit area 10) High mechanical stress pit 1990 Hawkins et al The efficiency of the process is low, with required for actuator 11) Unusual materials required U.S. Pat. No. 4,899,181 typically less than 0.05% of the electrical 12) Large drive transistors 18) Hewlett-Packard energy being transformed into kinetic 13) Cavitation causes actuator failure TIJ 1982 Vaught et al energy of the drop. 14) Kogation reduces bubble formation U.S. Pat. No. 4,490,728 15) Large print heads are difficult to fabricate Piezoelectric A piezoelectric crystal such as lead 19) Low power consumption 23) Very large area required for actuator 28) Kyser et al U.S. Pat. No. lanthanum zirconate (PZT) is electrically 20) Many ink types can be 24) Difficult to integrate with electronics 3,946,398 activated, and either expands, shears, or used 25) High voltage drive transistors 29) Zoltan U.S. Pat. No. bends to apply pressure to the ink, 21) Fast operation required 3,683,212 ejecting drops. 22) High efficiency 26) Full pagewidth print heads 30) 1973 Stemme impractical due to actuator size U.S. Pat. No. 3,747,120 27) Requires electrical poling in high 31) Epson Stylus field strengths during manufacture 32) Tektronix 33) IJ04 Electro-strictive An electric field is used to activate 34) Low power consumption 39) Low maximum strain (approx. 44) Seiko Epson, electrostriction in relaxor materials such 35) Many ink types can be 0.01%) Usui et all JP as lead lanthanum zirconate titanate used 40) Large area required for actuator due 253401/96 (PLZT) or lead magnesium niobate 36) Low thermal expansion to low strain 45) IJ04 (PMN). 37) Electric field strength 41) Response speed is marginal (˜10 μs) required (approx. 3.5 V/μm) 42) High voltage drive transistors can be generated without required difficulty 43) Full pagewidth print heads 38) Does not require electrical poling impractical due to actuator size Ferroelectric An electric field is used to induce a 46) Low power consumption 52) Difficult to integrate with electronics 55) IJ04 phase transition between the 47) Many ink types can be 53) Unusual materials such as PLZSnT antiferroelectric (AFE) and ferroelectric used are required (FE) phase. Perovskite materials such as 48) Fast operation (<1 μs) 54) Actuators require a large area tin modified lead lanthanum zirconate 49) Relatively high titanate (PLZSnT) exhibit large strains of longitudinal strain up to 1% associated with the AFE to FE 50) High efficiency phase transition. 51) Electric field strength of around 3 V/μm can be readily provided Electrostatic Conductive plates are separated by a 56) Low power consumption 59) Difficult to operate electrostatic 64) IJ02, IJ04 plates compressible or fluid dielectric (usually 57) Many ink types can be devices in an aqueous environment air). Upon application of a voltage, the used 60) The electrostatic actuator will plates attract each other and displace ink, 58) Fast operation normally need to be separated from the ink causing drop ejection. The conductive 61) Very large area required to achieve plates may be in a comb or honeycomb high forces structure, or stacked to increase the 62) High voltage drive transistors may be surface area and therefore the force. required 63) Full pagewidth print heads are not competitive due to actuator size Electrostatic pull A strong electric field is applied to the 65) Low current 67) High voltage required 72) 1989 Saito et al, on ink ink, whereupon electrostatic attraction consumption 68) May be damaged by sparks due to air U.S. Pat. No. 4,799,068 accelerates the ink towards the print 66) Low temperature breakdown 73) 1989 Miura et al, medium. 69) Required field strength increases as U.S. Pat. No. 4,810,954 the drop size decreases 74) Tone-jet 70) High voltage drive transistors required 71) Electrostatic field attracts dust Permanent An electromagnet directly attracts a 75) Low power consumption 80) Complex fabrication 86) IJ07, IJ10 magnet electro- permanent magnet, displacing ink and 76) Many ink types can be 81) Permanent magnetic material such as magnetic causing drop ejection. Rare earth used Neodymium Iron Boron (NdFeB) required. magnets with a field strength around 1 77) Fast operation 82) High local currents required Tesla can be used. Examples are: 78) High efficiency 83) Copper metalization should be used Samarium Cobalt (SaCo) and magnetic 79) Easy extension from for long electromigration lifetime and low materials in the neodymium iron boron single nozzles to pagewidth resistivity family (NdFeB, NdDyFeBNb, print heads 84) Pigmented inks are usually infeasible NdDyFeB, etc) 85) Operating temperature limited to the Curie temperature (around 540 K) Soft magnetic core A solenoid induced a magnetic field in a 87) Low power consumption 92) Complex fabrication 98) IJ01, IJ05, IJ08, electro-magnetic soft magnetic core or yoke fabricated 88) Many ink types can be 93) Materials not usually present in a IJ10 from a ferrous material such as used CMOS fab such as NiFe, CoNiFe, or CoFe 99) IJ12, IJ14, IJ15, electroplated iron alloys such as CoNiFe 89) Fast operation are required IJ17 [1], CoFe, or NiFe alloys. Typically, the 90) High efficiency 94) High local currents required soft magnetic material is in two parts, 91) Easy extension from 95) Copper metalization should be used which are normally held apart by a single nozzles to pagewidth for long electromigration lifetime and low spring. When the solenoid is actuated, print heads resistivity the two parts attract, displacing the ink. 96) Electroplating is required 97) High saturation flux density is required (2.0-2.1 T is achievable with CoNiFe [1]) Magnetic The Lorenz force acting on a current 100) Low power consumption 105) Force acts as a twisting motion 110) IJ06, IJ11, IJ13, Lorenz force carrying wire in a magnetic field is 101) Many ink types can be 106) Typically, only a quarter of the IJ16 utilized. used solenoid length provides force in a useful This allows the magnetic field to be 102) Fast operation direction supplied externally to the print head, for 103) High efficiency 107) High local currents required example with rare earth permanent 104) Easy extension from 108) Copper metalization should be used magnets. single nozzles to pagewidth for long electromigration lifetime and low Only the current carrying wire need be print heads resistivity fabricated on the print-head, simplifying 109) Pigmented inks are usually infeasible materials requirements. Magneto-striction The actuator uses the giant 111) Many ink types can be 115) Force acts as a twisting motion 120) Fischenbeck, U.S. Pat. No. magnetostrictive effect of materials such used 116) Unusual materials such as Terfenol-D 4,032,929 as Terfenol-D (an alloy of terbium, 112) Fast operation are required 121) IJ25 dysprosium and iron developed at the 113) Easy extension from 117) High local currents required Naval Ordnance Laboratory, hence Ter- single nozzles to pagewidth 118) Copper metalization should be used Fe-NOL). For best efficiency, the print heads for long electromigration lifetime and low actuator should be pre-stressed to 114) High force is available resistivity approx. 8 MPa. 119) Pre-stressing may be required Surface tension Ink under positive pressure is held in a 122) Low power consumption 127) Requires supplementary force to 130) Silverbrook, EP reduction nozzle by surface tension. The surface 123) Simple construction effect drop separation 0771 658 A2 and tension of the ink is reduced below the 124) No unusual materials 128) Requires special ink surfactants related patent bubble threshold, causing the ink to required in fabrication 129) Speed may be limited by surfactant applications egress from the nozzle. 125) High efficiency properties 126) Easy extension from single nozzles to pagewidth print heads Viscosity The ink viscosity is locally reduced to 131) Simple construction 134) Requires supplementary force to 139) Silverbrook, EP reduction select which drops are to be ejected. A 132) No unusual materials effect drop separation 0771 658 A2 and viscosity reduction can be achieved required in fabrication 135) Requires special ink viscosity related patent electrothermally with most inks, but 133) Easy extension from properties applications special inks can be engineered for a single nozzles to pagewidth 136) High speed is difficult to achieve 100:1 viscosity reduction. print heads 137) Requires oscillating ink pressure 138) A high temperature difference (typically 80 degrees) is required Acoustic An acoustic wave is generated and 140) Can operate without a 141) Complex drive circuitry 146) 1993 Hadimioglu focussed upon the drop ejection region. nozzle plate 142) Complex fabrication et al, EUP 550,192 143) Low efficiency 147) 1993 Elrod et al, 144) Poor control of drop position EUP 572,220 145) Poor control of drop volume Thermoelastic An actuator which relies upon 148) Low power consumption 157) Efficient aqueous operation requires 160) IJ03, IJ09, IJ17, bend actuator differential thermal expansion upon 149) Many ink types can be a thermal insulator on the hot side IJ18 Joule heating is used. used 158) Corrosion prevention can be difficult 161) IJ19, IJ20, IJ21, 150) Simple planar fabrication 159) Pigmented inks may be infeasible, as IJ22 151) Small integrated circuit pigment particles may jam the bend 162) IJ23, IJ24, IJ27, area required for each actuator actuator IJ28 152) Fast operation 163) IJ29, IJ30, IJ31, 153) High efficiency IJ32 154) CMOS compatible 164) IJ33, IJ34, IJ35, voltages and currents IJ36 155) Standard MEMS 165) IJ37, IJ38, IJ39, processes can be used IJ40 156) Easy extension from 166) IJ41 single nozzles to pagewidth print heads High CTE A material with a very high coefficient of 167) High force can be 177) Requires special material (e.g. PTFE) 181) IJ09, IJ17, IJ18, thermoelastic thermal expansion (CTE) such as generated 178) Requires a PTFE deposition process, IJ20 actuator polytetrafluoroethylene (PTFE) is used. 168) PTFE is a candidate for which is not yet standard in ULSI fabs 182) IJ21, IJ22, IJ23, As high CTE materials are usually non- low dielectric constant 179) PTFE deposition cannot be followed IJ24 conductive, a heater fabricated from a insulation in ULSI with high temperature(above 350° C.) 183) IJ27, IJ28, IJ29, conductive material is incorporated. A 50 μm 169) Very low power processing IJ30 long PTFE bend actuator with consumption 180) Pigmented inks may be infeasible, as 184) IJ31, IJ42, IJ43, polysilicon heater and 15 mW power 170) Many ink types can be pigment particles may jam the bend IJ44 input can provide 180 μN force and 10 μm used actuator deflection. Actuator motions include: 171) Simple planar fabrication Bend 172) Small integrated circuit Push area required for each actuator Buckle 173) Fast operation Rotate 174) High efficiency 175) CMOS compatible voltages and currents 176) Easy extension from single nozzles to pagewidth print heads Conductive A polymer with a high coefficient of 185) High force can be 194) Requires special materials 199) IJ24 polymer thermal expansion (such as PTFE) is generated development (High CTE conductive thermoelastic doped with conducting substances to 186) Very low power polymer) actuator increase its conductivity to about 3 consumption 195) Requires a PTFE deposition process, orders of magnitude below that of 187) Many ink types can be which is not yet standard in ULSI fabs copper. The conducting polymer expands used 196) PTFE deposition cannot be followed when resistively heated. 188) Simple planar fabrication with high temperature (above 350° C.) Examples of conducting dopants include: 189) Small integrated circuit processing Carbon nanotubes area required for each actuator 197) Evaporation and CVD deposition Metal fibers 190) Fast operation techniques cannot be used Conductive polymers such as doped 191) High efficiency 198) Pigmented inks may be infeasible, as polythiophene 192) CMOS compatible pigment particles may jam the bend Carbon granules voltages and currents actuator 193) Easy extension from single nozzles to pagewidth print heads Shape memory A shape memory alloy such as TiNi (also 200) High force is available 206) Fatigue limits maximum number of 213) IJ26 alloy known as Nitinol - Nickel Titanium alloy (stresses of hundreds of MPa) cycles developed at the Naval Ordnance 201) Large strain is available 207) Low strain (1%) is required to extend Laboratory) is thermally switched (more than 3%) fatigue resistance between its weak martensitic state and its 202) High corrosion 208) Cycle rate limited by heat removal high stiffness austenic state. The shape of resistance 209) Requires unusual materials (TiNi) the actuator in its martensitic state is 203) Simple construction 210) The latent heat of transformation deformed relative to the austenic shape. 204) Easy extension from must be provided The shape change causes ejection of a single nozzles to pagewidth 211) High current operation drop. print heads 212) Requires pre-stressing to distort the 205) Low voltage operation martensitic state Linear Magnetic Linear magnetic actuators include the 214) Linear Magnetic 218) Requires unusual semiconductor 222) IJ12 Actuator Linear Induction Actuator (LIA), Linear actuators can be constructed materials such as soft magnetic alloys (e.g. Permanent Magnet Synchronous with high thrust, long travel, CoNiFe [1]) Actuator (LPMSA), Linear Reluctance and high efficiency using 219) Some varieties also require Synchronous Actuator (LRSA), Linear planar semiconductor permanent magnetic materials such as Switched Reluctance Actuator (LSRA), fabrication techniques Neodymium iron boron (NdFeB) and the Linear Stepper Actuator (LSA). 215) Long actuator travel is 220) Requires complex multi-phase drive available circuitry 216) Medium force is 221) High current operation available 217) Low voltage operation

BASIC OPERATION MODE Operational mode Description Advantages Disadvantages Examples Actuator directly This is the simplest mode of operation: 223) Simple operation 227) Drop repetition rate is usually limited 230) Thermal inkjet pushes ink the actuator directly supplies sufficient 224) No external fields to less than 10 KHz. However, this is not 231) Piezoelectric inkjet kinetic energy to expel the drop. The required fundamental to the method, but is related to 232) IJ01, IJ02, IJ03, IJ04 drop must have a sufficient velocity to 225) Satellite drops can be the refill method normally used 233) IJ05, IJ06, IJ07, IJ09 overcome the surface tension. avoided if drop velocity is less 228) All of the drop kinetic energy must 234) IJ11, IJ12, IJ14, IJ16 than 4 m/s be provided by the actuator 235) IJ20, IJ22, IJ23, IJ24 226) Can be efficient, 229) Satellite drops usually form if drop 236) IJ25, IJ26, IJ27, IJ28 depending upon the actuator used velocity is greater than 4.5 m/s 237) IJ29, IJ30, IJ31, IJ32 238) IJ33, IJ34, IJ35, IJ36 239) IJ37, IJ38, IJ39, IJ40 240) IJ41, IJ42, IJ43, IJ44 Proximity The drops to be printed are selected by 241) Very simple print head 243) Requires close proximity between the 246) Silverbrook, EP some manner (e.g. thermally induced fabrication can be used print head and the print media or transfer 0771 658 A2 and surface tension reduction of pressurized 242) The drop selection roller related patent ink). Selected drops are separated from means does not need to 244) May require two print heads printing applications the ink in the nozzle by contact with the provide the energy required to alternate rows of the image print medium or a transfer roller. separate the drop from the nozzle 245) Monolithic color print heads are difficult Electrostatic pull on ink The drops to be printed are selected by 247) Very simple print head 249) Requires very high electrostatic field 252) Silverbrook, EP some manner (e.g. thermally induced fabrication can be used 250) Electrostatic field for small nozzle 0771 658 A2 and surface tension reduction of pressurized 248) The drop selection sizes is above air breakdown related patent ink). Selected drops are separated from means does not need to 251) Electrostatic field may attract dust applications the ink in the nozzle by a strong electric provide the energy required to 253) Tone-Jet field. separate the drop from the nozzle Magnetic pull on The drops to be printed are selected by 254) Very simple print head 256) Requires magnetic ink 259) Silverbrook, EP ink some manner (e.g. thermally induced fabrication can be used 257) Ink colors other than black are 0771 658 A2 and surface tension reduction of pressurized 255) The drop selection difficult related patent ink). Selected drops are separated from means does not need to 258) Requires very high magnetic fields applications the ink in the nozzle by a strong provide the energy required to magnetic field acting on the magnetic ink. separate the drop from the nozzle Shutter The actuator moves a shutter to block ink 260) High speed (>50 KHz) 263) Moving parts are required 267) IJ13, IJ17, IJ21 flow to the nozzle. The ink pressure is operation can be achieved due 264) Requires ink pressure modulator pulsed at a multiple of the drop ejection to reduced refill time 265) Friction and wear must be considered frequency. 261) Drop timing can be very 266) Stiction is possible accurate 262) The actuator energy can be very low Shuttered grill The actuator moves a shutter to block ink 268) Actuators with small 271) Moving parts are required 275) IJ08, IJ15, IJ18, IJ19 flow through a grill to the nozzle. The travel can be used 272) Requires ink pressure modulator shutter movement need only be equal to 269) Actuators with small 273) Friction and wear must be considered the width of the grill holes. force can be used 274) Stiction is possible 270) High speed (>50 KHz) operation can be achieved Pulsed magnetic A pulsed magnetic field attracts an ‘ink 276) Extremely low energy 278) Requires an external pulsed magnetic 281) IJ10 pull on ink pusher pusher’ at the drop ejection frequency. operation is possible field An actuator controls a catch, which 277) No heat dissipation 279) Requires special materials for both prevents the ink pusher from moving problems the actuator and the ink pusher when a drop is not to be ejected. 280) Complex construction

AUXILIARY MECHANISM (APPLIED TO ALL NOZZLES) Auxiliary Mechanism Description Advantages Disadvantages Examples None The actuator directly fires the ink drop, 282) Simplicity of 285) Drop ejection energy must be 286) Most inkjets, and there is no external field or other construction supplied by individual nozzle actuator including piezoelectric mechanism required. 283) Simplicity of operation and thermal bubble. 284) Small physical size 287) IJ01-IJ07, IJ09, IJ11 288) IJ12, IJ14, IJ20, IJ22 289) IJ23-IJ45 Oscillating ink The ink pressure oscillates, providing 290) Oscillating ink pressure 293) Requires external ink pressure 296) Silverbrook, EP pressure much of the drop ejection energy. The can provide a refill pulse, oscillator 0771 658 A2 and (including actuator selects which drops are to be allowing higher operating 294) Ink pressure phase and amplitude related patent acoustic stimulation) fired by selectively blocking or enabling speed must be carefully controlled applications nozzles. The ink pressure oscillation may 291) The actuators may 295) Acoustic reflections in the ink 297) IJ08, IJ13, IJ15, be achieved by vibrating the print head, operate with much lower chamber must be designed for IJ17 or preferably by an actuator in the ink energy 298) IJ18, IJ19, IJ21 supply. 292) Acoustic lenses can be used to focus the sound on the nozzles Media proximity The print head is placed in close 299) Low power 302) Precision assembly required 305) Silverbrook, EP proximity to the print medium. Selected 300) High accuracy 303) Paper fibers may cause problems 0771 658 A2 and drops protrude from the print head 301) Simple print head 304) Cannot print on rough substrates related patent further than unselected drops, and construction applications contact the print medium. The drop soaks into the medium fast enough to cause drop separation. Transfer roller Drops are printed to a transfer roller 306) High accuracy 309) Bulky 312) Silverbrook, EP instead of straight to the print medium. A 307) Wide range of print 310) Expensive 0771 658 A2 and transfer roller can also be used for substrates can be used 311) Complex construction related patent proximity drop separation. 308) Ink can be dried on the applications transfer roller 313) Tektronix hot melt piezoelectric inkjet 314) Any of the IJ series Electrostatic An electric field is used to accelerate 315) Low power 317) Field strength required for separation 318) Silverbrook, EP selected drops towards the print medium. 316) Simple print head of small drops is near or above air 0771 658 A2 and construction breakdown related patent applications 319) Tone-Jet Direct magnetic A magnetic field is used to accelerate 320) Low power 322) Requires magnetic ink 324) Silverbrook, EP field selected drops of magnetic ink towards 321) Simple print head 323) Requires strong magnetic field 0771 658 A2 and the print medium. construction related patent applications Cross magnetic The print head is placed in a constant 325) Does not require 326) Requires external magnet 328) IJ06, IJ16 field magnetic field. The Lorenz force in a magnetic materials to be 327) Current densities may be high, current carrying wire is used to move the integrated in the print head resulting in electromigration problems actuator. manufacturing process Pulsed magnetic A pulsed magnetic field is used to 329) Very low power 331) Complex print head construction 333) IJ10 field cyclically attract a paddle, which pushes operation is possible 332) Magnetic materials required in print on the ink. A small actuator moves a 330) Small print head size head catch, which selectively prevents the paddle from moving.

ACTUATOR AMPLIFICATION OR MODIFICATION METHOD Actuator amplification Description Advantages Disadvantages Examples None No actuator mechanical amplification is 334) Operational simplicity 335) Many actuator mechanisms have 336) Thermal Bubble used. The actuator directly drives the insufficient travel, or insufficient force, to Inkjet drop ejection process. efficiently drive the drop ejection process 337) IJ01, IJ02, IJ06, IJ07 338) IJ16, IJ25, IJ26 Differential An actuator material expands more on 339) Provides greater travel in 341) High stresses are involved 344) Piezoelectric expansion bend actuator one side than on the other. The a reduced print head area 342) Care must be taken that the materials 345) IJ03, IJ09, IJ17-IJ24 expansion may be thermal, piezoelectric, 340) The bend actuator do not delaminate magnetostrictive, or other mechanism, converts a high force low 343) Residual bend resulting from high 346) IJ27, IJ29-IJ39, travel actuator mechanism to temperature or high stress during formation IJ42, high travel, lower force 347) IJ43, IJ44 mechanism. Transient bend actuator A trilayer bend actuator where the two 348) Very good temperature 351) High stresses are involved 353) IJ40, IJ41 outside layers are identical. This cancels stability 352) Care must be taken that the materials bend due to ambient temperature and 349) High speed, as a new do not delaminate residual stress. The actuator only drop can be fired before heat responds to transient heating of one side or the dissipates other. 350) Cancels residual stress of formation Actuator stack A series of thin actuators are stacked. 354) Increased travel 356) Increased fabrication complexity 358) Some This can be appropriate where actuators 355) Reduced drive voltage 357) Increased possibility of short circuits piezoelectric ink jets require high electric field strength, such due to pinholes 359) IJ04 as electrostatic and piezoelectric actuators. Multiple actuators Multiple smaller actuators are used 360) Increases the force 362) Actuator forces may not add linearly, 363) IJ12, IJ13, IJ18, simultaneously to move the ink. Each available from an actuator reducing efficiency IJ20 actuator need provide only a portion of 361) Multiple actuators can be 364) IJ22, IJ28, IJ42, the force required. positioned to control ink flow IJ43 accurately Linear Spring A linear spring is used to transform a 365) Matches low travel 367) Requires print head area for the 368) IJ15 motion with small travel and high force actuator with higher travel spring into a longer travel, lower force motion. requirements 366) Non-contact method of motion transformation Reverse spring The actuator loads a spring. When the 369) Better coupling to the 370) Fabrication complexity 372) IJ05, IJ11 actuator is turned off, the spring releases. ink 371) High stress in the spring This can reverse the force/distance curve of the actuator to make it compatible with the force/time requirements of the drop ejection. Coiled actuator A bend actuator is coiled to provide 373) Increases travel 376) Generally restricted to planar 377) IJ17, IJ21, IJ34, greater travel in a reduced integrated 374) Reduces integrated implementations due to extreme fabrication IJ35 circuit area. circuit area difficulty in other orientations. 375) Planar implementations are relatively easy to fabricate. Flexure bend A bend actuator has a small region near 378) Simple means of 379) Care must be taken not to exceed the 382) IJ10, IJ19, IJ33 actuator the fixture point, which flexes much increasing travel of a bend elastic limit in the flexure area more readily than the remainder of the actuator 380) Stress distribution is very uneven actuator. The actuator flexing is 381) Difficult to accurately model with effectively converted from an even finite element analysis coiling to an angular bend, resulting in greater travel of the actuator tip. Gears Gears can be used to increase travel at 383) Low force, low travel 385) Moving parts are required 390) IJ13 the expense of duration. Circular gears, actuators can be used 386) Several actuator cycles are required rack and pinion, ratchets, and other 384) Can be fabricated using 387) More complex drive electronics gearing methods can be used. standard surface MEMS 388) Complex construction processes 389) Friction, friction, and wear are possible Catch The actuator controls a small catch. The 391) Very low actuator energy 393) Complex construction 396) IJ10 catch either enables or disables 392) Very small actuator size 394) Requires external force movement of an ink pusher that is 395) Unsuitable for pigmented inks controlled in a bulk manner. Buckle plate A buckle plate can be used to change a 397) Very fast movement 398) Must stay within elastic limits of the 401) S. Hirata et al, slow actuator into a fast motion. It can achievable materials for long device life “An Ink-jet Head . . . ”, also convert a high force, low travel 399) High stresses involved Proc. IEEE MEMS, actuator into a high travel, medium force 400) Generally high power requirement Feb. 1996, pp 418-423. motion. 402) IJ18, IJ27 Tapered magnetic A tapered magnetic pole can increase 403) Linearizes the magnetic 404) Complex construction 405) IJ14 pole travel at the expense of force. force/distance curve Lever A lever and fulcrum is used to transform 406) Matches low travel 408) High stress around the fulcrum 409) IJ32, IJ36, IJ37 a motion with small travel and high force actuator with higher travel into a motion with longer travel and requirements lower force. The lever can also reverse 407) Fulcrum area has no the direction of travel. linear movement, and can be used for a fluid seal Rotary impeller The actuator is connected to a rotary 410) High mechanical 412) Complex construction 414) IJ28 impeller. A small angular deflection of advantage 413) Unsuitable for pigmented inks the actuator results in a rotation of the 411) The ratio of force to impeller vanes, which push the ink travel of the actuator can be against stationary vanes and out of the matched to the nozzle nozzle. requirements by varying the number of impeller vanes Acoustic lens A refractive or diffractive (e.g. zone 415) No moving parts 416) Large area required 418) 1993 Hadimioglu plate) acoustic lens is used to concentrate 417) Only relevant for acoustic ink jets et al, EUP 550, 192 sound waves. 419) 1993 Elrod et al, EUP 572, 220 Sharp conductive A sharp point is used to concentrate an 420) Simple construction 421) Difficult to fabricate using standard 423) Tone-jet point electrostatic field. VLSI processes for a surface ejecting ink- jet 422) Only relevant for electrostatic ink jets

ACTUATOR MOTION Actuator motion Description Advantages Disadvantages Examples Volume expansion The volume of the actuator changes, 424) Simple construction in 425) High energy is typically required to 426) Hewlett-Packard pushing the ink in all directions. the case of thermal ink jet achieve volume expansion. This leads to Thermal Inkjet thermal stress, cavitation, and kogation in 427) Canon Bubblejet thermal ink jet implementations Linear, normal to The actuator moves in a direction normal 428) Efficient coupling to ink 429) High fabrication complexity may be 430) IJ01, IJ02, IJ04, integrated circuit to the print head surface. The nozzle is drops ejected normal to the required to achieve perpendicular motion IJ07 surface typically in the line of movement. surface 431) IJ11, IJ14 Linear, parallel to The actuator moves parallel to the print 432) Suitable for planar 433) Fabrication complexity 436) IJ12, IJ13, IJ15, integrated circuit head surface. Drop ejection may still be fabrication 434) Friction IJ33, surface normal to the surface. 435) Stiction 437) IJ34, IJ35, IJ36 Membrane push An actuator with a high force but small 438) The effective area of the 439) Fabrication complexity 442) 1982 Howkins area is used to push a stiff membrane that actuator becomes the 440) Actuator size U.S. Pat. No. 4,459,601 is in contact with the ink, membrane area 441) Difficulty of integration in a VLSI process Rotary The actuator causes the rotation of some 443) Rotary levers may be 445) Device complexity 447) IJ05, 1J08, IJ13, element, such a grill or impeller used to increase travel 446) May have friction at a pivot point IJ28 444) Small integrated circuit area requirements Bend The actuator bends when energized. This 448) A very small change in 449) Requires the actuator to be made 450) 1970 Kyser et al may be due to differential thermal dimensions can be converted to from at least two distinct layers, or to have U.S. Pat. No. 3,946,398 expansion, piezoelectric expansion, a large motion, a thermal difference across the actuator 451) 1973 Stemme magnetostriction, or other form of U.S. Pat. No. 3,747,120 relative dimensional change. 452) IJ03, IJ09, IJ10, IJ19 453) IJ23, IJ24, IJ25, IJ29 454) IJ30, IJ31, IJ33, IJ34 455) IJ35 Swivel The actuator swivels around a central 456) Allows operation where 458) Inefficient coupling to the ink motion 459) IJ06 pivot. This motion is suitable where there the net linear force on the are opposite forces applied to opposite paddle is zero sides of the paddle, e.g. Lorenz force. 457) Small integrated circuit area requirements Straighten The actuator is normally bent, and 460) Can be used with shape 461) Requires careful balance of stresses 462) IJ26, IJ32 straightens when energized. memory alloys where the to ensure that the quiescent bend is austenic phase is planar accurate Double bend The actuator bends in one direction when 463) One actuator can be used 466) Difficult to make the drops ejected by 468) IJ36, IJ37, IJ38 one element is energized, and bends the to power two nozzles. both bend directions identical. other way when another element is 464) Reduced integrated 467) A small efficiency loss compared to energized. circuit size. equivalent single bend actuators. 465) Not sensitive to ambient temperature Shear Energizing the actuator causes a shear 469) Can increase the 470) Not readily applicable to other 471) 1985 Fishbeck motion in the actuator material. effective travel of piezoelectric actuator mechanisms U.S. Pat. No. 4,584,590 actuators Radial The actuator squeezes an ink reservoir, 472) Relatively easy to 473) High force required 476) 1970 Zoltan U.S. Pat. No. constriction forcing ink from a constricted nozzle. fabricate single nozzles from 474) Inefficient 3,683,212 glass tubing as macroscopic 475) Difficult to integrate with VLSI structures processes Coil/uncoil A coiled actuator uncoils or coils more 477) Easy to fabricate as a 479) Difficult to fabricate for non-planar 481) IJ17, IJ21, IJ34, tightly. The motion of the free end of the planar VLSI process devices IJ35 actuator ejects the ink. 478) Small area required, 480) Poor out-of-plane stiffness therefore low cost Bow The actuator bows (or buckles) in the 482) Can increase the speed 484) Maximum travel is constrained 486) IJ16, IJ18, IJ27 middle when energized. of travel 485) High force required 483) Mechanically rigid Push-Pull Two actuators control a shutter. One 487) The structure is pinned at 488) Not readily suitable for inkjets which 489) IJ18 actuator pulls the shutter, and the other both ends, so has a high out-of- directly push the ink pushes it. plane rigidity Curl inwards A set of actuators curl inwards to reduce 490) Good fluid flow to the 491) Design complexity 492) IJ20, IJ42 the volume of ink that they enclose. region behind the actuator increases efficiency Curl outwards A set of actuators curl outwards, 493) Relatively simple 494) Relatively large integrated circuit 495) IJ43 pressurizing ink in a chamber construction area surrounding the actuators, and expelling ink from a nozzle in the chamber. Iris Multiple vanes enclose a volume of ink. 496) High efficiency 498) High fabrication complexity 500) IJ22 These simultaneously rotate, reducing 497) Small integrated circuit 499) Not suitable for pigmented inks the volume between the vanes. area Acoustic vibration The actuator vibrates at a high frequency. 501) The actuator can be 502) Large area required for efficient 506) 1993 Hadimioglu physically distant from the ink operation at useful frequencies et al, EUP 550,192 503) Acoustic coupling and crosstalk 507) 1993 Elrod et al, 504) Complex drive circuitry EUP 572,220 505) Poor control of drop volume and position None In various ink jet designs the actuator does not move. 508) No moving parts 509) Various other tradeoffs are required 510) Silverbrook, EP to eliminate moving parts 0771 658 A2 and related patent applications 511) Tone-jet

NOZZLE REFILL METHOD Nozzle refill method Description Advantages Disadvantages Examples Surface After the actuator is 512) Fabrication simplicity 514) Low speed 517) Thermal inkjet tension energized, it typically returns 513) Operational simplicity 515) Surface tension force relatively 518) Piezoelectric rapidly to its normal position. small compared to actuator force inkjet This rapid return sucks in air 516) Long refill time usually dominates 519) IJ01-IJ07, IJ10-IJ14 through the nozzle opening. the total repetition rate 520) IJ16, IJ20, IJ22-IJ45 The ink surface tension at the nozzle then exerts a small force restoring the meniscus to a minimum area. Shuttered Ink to the nozzle chamber is 521) High speed 523) Requires common ink pressure 525) IJ08, IJ13, IJ15, oscillating provided at a pressure that 522) Low actuator oscillator IJ17 ink oscillates at twice the drop energy, as the actuator 524) May not be suitable for pigmented 526) IJ18, IJ19, IJ21 pressure ejection frequency. When need only open or inks a drop is to be ejected, close the shutter, the shutter is opened for 3 instead of ejecting half cycles: drop ejection, the ink drop actuator return, and refill. Refill After the main actuator has 527) High speed, as 528) Requires two independent actuators 529) IJ09 actuator ejected a drop a second the nozzle is per nozzle (refill) actuator is energized. actively refilled The refill actuator pushes ink into the nozzle chamber. The refill actuator returns slowly, to prevent its return from emptying the chamber again. Positive The ink is held a slight 530) High refill rate, 531) Surface spill must be prevented 533) Silverbrook, EP ink positive pressure. After the therefore a high drop 532) Highly hydrophobic print head 0771 658 A2 and pressure ink drop is ejected, the repetition rate is surfaces are required related patent nozzle chamber fills quickly possible applications as surface tension 534) Alternative for: and ink pressure 535) IJ01-IJ07, IJ10-IJ14 both operate to 536) IJ16, IJ20, IJ22-IJ45 refill the nozzle.

METHOD OF RESTRICTING BACK-FLOW THROUGH INLET Inlet back-flow restriction method Description Advantages Disadvantages Examples Long inlet channel The ink inlet channel to the nozzle 537) Design simplicity 540) Restricts refill rate 543) Thermal inkjet chamber is made long and relatively 538) Operational simplicity 541) May result in a relatively large 544) Piezoelectric narrow, relying on viscous drag to reduce inlet back-flow. 539) Reduces crosstalk integrated circuit area inkjet 542) Only partially effective 545) IJ42, IJ43 Positive ink The ink is under a positive pressure, so 546) Drop selection and 548) Requires a method (such as a nozzle 549) Silverbrook, EP pressure that in the quiescent state some of the ink separation forces can be rim or effective hydrophobizing, or both) to 0771 658 A2 and drop already protrudes from the nozzle. reduced prevent flooding of the ejection surface of related patent This reduces the pressure in the nozzle 547) Fast refill time the print head. applications chamber which is required to eject a certain volume of 550) Possible operation ink. The reduction in chamber pressure results in a of the following: reduction in ink pushed out through the inlet. 551) IJ01-IJ07, IJ09-IJ12 552) IJ14, IJ16, IJ20, IJ22, 553) IJ23-IJ34, IJ36-IJ41 554) IJ44 Baffle One or more baffles are placed in the 555) The refill rate is not as 557) Design complexity 559) HP Thermal Ink inlet ink flow. When the actuator is restricted as the long inlet 558) May increase fabrication complexity Jet energized, the rapid ink movement method. (e.g. Tektronix hot melt Piezoelectric print 560) Tektronix creates eddies which restrict the flow 556) Reduces crosstalk heads). piezoelectric ink jet through the inlet. The slower refill process is unrestricted, and does not result in eddies. Flexible flap In this method recently disclosed by 561) Significantly reduces 562) Not applicable to most inkjet 565) Canon restricts inlet Canon, the expanding actuator (bubble) back-flow for edge-shooter configurations pushes on a flexible flap that restricts the thermal ink jet devices 563) Increased fabrication complexity inlet. 564) Inelastic deformation of polymer flap results in creep over extended use Inlet filter A filter is located between the ink inlet 566) Additional advantage of 568) Restricts refill rate 570) IJ04, IJ12, IJ24, and the nozzle chamber. The filter has a ink filtration 569) May result in complex construction IJ27 multitude of small holes or slots, 567) Ink filter may be 571) IJ29, IJ30 restricting ink flow. The filter also fabricated with no additional removes particles which may block the process steps nozzle. Small inlet The ink inlet channel to the nozzle 572) Design simplicity 573) Restricts refill rate 576) IJ02, IJ37, IJ44 compared to chamber has a substantially smaller cross 574) May result in a relatively large nozzle section than that of the nozzle, resulting integrated circuit area in easier ink egress out of the nozzle than 575) Only partially effective out of the inlet. Inlet shutter A secondary actuator controls the 577) Increases speed of the 578) Requires separate refill actuator and 579) IJ09 position of a shutter, closing off the ink ink-jet print head operation drive circuit inlet when the main actuator is energized. The inlet is The method avoids the problem of inlet 580) Back-flow problem is 581) Requires careful design to minimize 582) IJ01, IJ03, IJ05, located behind the back-flow by arranging the ink-pushing eliminated the negative pressure behind the paddle IJ06 ink-pushing surface of the actuator between the inlet 583) IJ07, IJ10, IJ11, surface and the nozzle. IJ14 584) IJ16, IJ22, IJ23, IJ25 585) IJ28, IJ31, IJ32, IJ33 586) IJ34, IJ35, IJ36, IJ39 587) IJ40, IJ41 Part of the The actuator and a wall of the ink 588) Significant reductions in 590) Small increase in fabrication 591) IJ07, IJ20, IJ26, actuator moves to chamber are arranged so that the motion back-flow can be achieved complexity IJ38 shut off the inlet of the actuator closes off the inlet. 589) Compact designs possible Nozzle actuator In some configurations of ink jet, there is 592) Ink back-flow problem is 593) None related to ink back-flow on 594) Silverbrook, EP does not result in no expansion or movement of an actuator eliminated actuation 0771 658 A2 and ink back-flow which may cause ink back-flow through the inlet. related patent applications 595) Valve-jet 596) Tone-jet 597) IJ08, IJ13, IJ15, IJ17 598) IJ18, IJ19, IJ21

NOZZLE CLEARING METHOD Nozzle Clearing method Description Advantages Disadvantages Examples Normal nozzle firing All of the nozzles are fired periodically, before the 599) No added complexity on 600) May not be sufficient to displace 601) Most ink jet ink has a chance to dry. When not in use the nozzles the print head dried ink systems are sealed (capped) against air. The nozzle firing is 602) IJ01-IJ07, IJ09-IJ12 usually performed duringa special clearing cycle, after 603) IJ14, IJ16, IJ20, IJ22 first moving the print head to a cleaning station. 604) IJ23-IJ34, IJ36-IJ45 Extra power to ink heater In systems which heat the ink, but do not 605) Can be highly effective 606) Requires higher drive voltage for 608) Silverbrook, EP boil it under normal situations, nozzle if the heater is adjacent to the clearing 0771 658 A2 and clearing can be achieved by over-powering nozzle 607) May require larger drive transistors related patent the heater and boiling ink at the nozzle. applications Rapid succession of The actuator is fired in rapid succession. 609) Does not require extra 611) Effectiveness depends substantially 612) May be used with: actuator pulses In some configurations, this may cause heat drive circuits on the print head upon the configuration of the inkjet nozzle 613) IJ01-IJ07, IJ09-IJ11 build-up at the nozzle which boils the ink, 610) Can be readily controlled 614) IJ14, IJ16, IJ20, IJ22 clearing the nozzle. In other situations, it may cause and initiated by digital logic 615) IJ23-IJ25, IJ27-IJ34 sufficient vibrations to dislodge clogged nozzles. 616) IJ36-IJ45 Extra power to ink pushing Where an actuator is not normally driven 617) A simple solution where 618) Not suitable where there is a hard 619) May be used with: actuator to the limit of its motion, nozzle clearing applicable limit to actuator movement 620) IJ03, IJ09, IJ16, IJ20 may be assisted by providing an 621) IJ23, IJ24, IJ25, IJ27 enhanced drive signal to the actuator. 622) IJ29, IJ30, IJ31, IJ32 623) IJ39, IJ40, IJ41, IJ42 624) IJ43, IJ44, IJ45 Acoustic resonance An ultrasonic wave is applied to the ink chamber. 625) A high nozzle clearing 627) High implementation cost if system 628) IJ08, IJ13, IJ15, This wave is of an appropriate amplitude and capability can be achieved does not already include an acoustic IJ17 frequency to cause sufficient force at the 626) May be implemented at actuator 629) IJ18, IJ19, IJ21 nozzle to clear blockages. This is the easiest very low cost in systems which to achieve if the ultrasonic wave is at a resonant already include acoustic frequency of the ink cavity. actuators Nozzle clearing plate A microfabricated plate is pushed against 630) Can clear severely 631) Accurate mechanical alignment is required 635) Silverbrook, EP the nozzles. The plate has a post for clogged nozzles 632) Moving parts are required 0771 658 A2 and every nozzle. The array of posts 633) There is risk of damage to the nozzles related patent 634) Accurate fabrication is required applications Ink pressure pulse The pressure of the ink is temporarily 636) May be effective where 637) Requires pressure pump or other 640) May be used with increased so that ink streams from all of other methods cannot be used pressure actuator all IJ series ink jets the nozzles. This may be used in 638) Expensive conjunction with actuator energizing. 639) Wasteful of ink Print head wiper A flexible ‘blade’ is wiped across the 641) Effective for planar print 643) Difficult to use if print head surface 646) Many ink jet print head surface. The blade is usually head surfaces is non-planar or very fragile systems fabricated from a flexible polymer, e.g. 642) Low cost 644) Requires mechanical parts rubber or synthetic elastomer. 645) Blade can wear out in high volume print systems Separate ink boiling A separate heater is provided at the nozzle 647) Can be effective where 649) Fabrication complexity 650) Can be used with heater although the normal drop e-ection mechanism does other nozzle clearing methods many IJ series ink jets not require it. The heaters do not require cannot be used individual drive circuits, as many nozzles 648) Can be implemented at no can be cleared simultaneously, additional cost in some and no imaging is required. inkjet configurations

NOZZLE PLATE CONSTRUCTION Nozzle plate construction Description Advantages Disadvantages Examples Electroformed A nozzle plate is 651) Fabrication 652) High temperatures and 655) Hewlett Packard nickel separately fabricated simplicity pressures are required to bond nozzle Thermal Inkjet from electroformed plate nickel, and bonded to 653) Minimum thickness constraints the print head 654) Differential thermal expansion integrated circuit. Laser ablated Individual nozzle holes 656) No masks required 660) Each hole must be individually 664) Canon Bubblejet or drilled are ablated by an 657) Can be quite fast formed 665) 1988 Sercel et al., polymer intense UV laser in a 658) Some control over 661) Special equipment required SPIE, Vol. 998 nozzle plate, which is nozzle profile is possible 662) Slow where there are many Excimer Beam typically a polymer 659) Equipment required is thousands of nozzles per print head Applications, such as polyimide or relatively low cost 663) May produce thin burrs at exit holes 666) pp. 76-83 polysulphone 1993 Watanabe et al., U.S. Pat. No. 5,208,604 Silicon A separate nozzle plate 667) High accuracy is 668) Two part construction 672) K. Bean, IEEE micromachined is micromachined from attainable 669) High cost Transactions on single crystal silicon, 670) Requires precision alignment Electron Devices, and bonded to the print 671) Nozzles may be clogged by adhesive Vol. ED-25, No. 10, head wafer. 1978, pp 1185-1195 673) Xerox 1990 Hawkins et al., U.S. Pat. No. 4,899,181 Glass Fine glass capillaries 674) No expensive equipment 676) Very small nozzle sizes are difficult 678) 1970 Zoltan U.S. capillaries are drawn from glass required to form Pat. No. 3,683,212 tubing. This method 675) Simple to make single 677) Not suited for mass production has been used for nozzles making individual nozzles, but is difficult to use for bulk manufacturing of print heads with thousands of nozzles. Monolithic, The nozzle plate is 679) High accuracy (<1 μm) 683) Requires sacrificial layer under the 685) Silverbrook, EP surface deposited as a layer 680) Monolithic nozzle plate to form the nozzle 0771 658 A2 and micromachined using standard VLSI 681) Low cost chamber related patent using VLSI deposition techniques. 682) Existing processes can 684) Surface may be fragile to the touch applications lithographic Nozzles are etched in be used 686) IJ01, IJ02, IJ04, processes the nozzle plate using IJ11 VLSI lithography and 687) IJ12, IJ17, IJ18, etching. IJ20 688) IJ22, IJ24, IJ27, IJ28 689) IJ29, IJ30, IJ31, IJ32 690) IJ33, IJ34, IJ36, IJ37 691) IJ38, IJ39, IJ40, IJ41 692) IJ42, IJ43, IJ44 Monolithic, The nozzle plate is a 693) High accuracy (<1 μm) 697) Requires long etch times 699) IJ03, IJ05, IJ06, etched through buried etch stop in the 694) Monolithic 698) Requires a support wafer IJ07 substrate wafer. Nozzle 695) Low cost 700) IJ08, IJ09, IJ10, chambers are etched in 696) No differential IJ13 the front of the wafer, expansion 701) IJ14, IJ15, IJ16, and the wafer is IJ19 thinned from the back 702) IJ21, IJ23, IJ25, side. Nozzles are then IJ26 etched in the etch stop layer. No nozzle plate Various methods have 703) No nozzles to become 704) Difficult to control drop position 706) Ricoh 1995 been tried to eliminate clogged accurately Sekiya et al U.S. the nozzles entirely, to 705) Crosstalk problems Pat. No. 5,412,413 prevent nozzle 707) 1993 Hadimioglu clogging. These et al EUP 550,192 include thermal 708) 1993 Elrod et al bubble mechanisms EUP 572,220 and acoustic lens mechanisms Trough Each drop ejector has 709) Reduced manufacturing 711) Drop firing direction is sensitive to 712) IJ35 a trough through complexity wicking. which a paddle moves. 710) Monolithic There is no nozzle plate. Nozzle slit The elimination of 713) No nozzles to become 714) Difficult to control drop position 716) 1989 Saito et al instead of nozzle holes and clogged accurately U.S. Pat. No. individual replacement by a slit 715) Crosstalk problems 4,799,068 nozzles encompassing many actuator positions reduces nozzle clogging, but increases crosstalk due to ink surface waves

DROP EJECTION DIRECTION Ejection direction Description Advantages Disadvantages Examples Edge Ink flow is along 717) Simple construction 722) Nozzles limited to edge 725) Canon Bubblejet (‘edge the surface of the 718) No silicon etching 723) High resolution is difficult 1979 Endo et al GB shooter’) integrated circuit, and required 724) Fast color printing requires one print patent 2,007,162 ink drops are ejected 719) Good heat sinking via head per color 726) Xerox heater-in- from the integrated substrate pit 1990 Hawkins et al circuit edge. 720) Mechanically strong U.S. Pat. No. 4,899,181 721) Ease of integrated circuit 727) Tone-jet handing Surface Ink flow is along 728) No bulk silicon etching 731) Maximum ink flow is severely 732) Hewlett-Packard (‘roof the surface of the required restricted TIJ 1982 Vaught et al shooter’) integrated circuit, and 729) Silicon can make an U.S. Pat. No. 4,490,728 ink drops are ejected effective heat sink 733) IJ02, IJ11, IJ12, from the integrated 730) Mechanical strength IJ20 circuit surface, 734) IJ22 normal to the plane of the integrated circuit. Through Ink flow is through 735) High ink flow 738) Requires bulk silicon etching 739) Silverbrook, EP integrated the integrated circuit, 736) Suitable for pagewidth 0771 658 A2 and circuit, and ink drops are print related patent forward ejected from the 737) High nozzle packing applications (‘up front surface of density therefore low 740) IJ04, IJ17, IJ18, shooter’) the integrated manufacturing cost IJ24 circuit. 741) IJ27-IJ45 Through Ink flow is through 742) High ink flow 745) Requires wafer thinning 747) IJ01, IJ03, IJ05, integrated the integrated circuit, 743) Suitable for pagewidth 746) Requires special handling during IJ06 circuit, and ink drops are print manufacture 748) IJ07, IJ08, IJ09, reverse ejected from the rear 744) High nozzle packing IJ10 (‘down surface of the density therefore low 749) IJ13, IJ14, IJ15, shooter’) integrated circuit. manufacturing cost IJ16 750) IJ19, IJ21, IJ23, IJ25 751) IJ26 Through Ink flow is through 752) Suitable for piezoelectric 753) Pagewidth print heads require several 756) Epson Stylus actuator the actuator, which is not print heads thousand connections to drive circuits 757) Tektronix hot fabricated as part of 754) Cannot be manufactured in standard melt piezoelectric ink the same substrate CMOS fabs jets as the drive 755) Complex assembly required transistors.

INK TYPE Ink type Description Advantages Disadvantages Examples Aqueous, dye Water based ink which typically 758) Environmentally friendly 760) Slow drying 765) Most existing inkjets contains: water, dye, surfactant, 759) No odor 761) Corrosive 766) All IJ series ink jets humectant, and biocide. 762) Bleeds on paper 767) Silverbrook, EP Modern ink dyes have high water- 763) May strikethrough 0771 658 A2 and fastness, light fastness 764) Cockles paper related patent applications Aqueous, pigment Water based ink which typically 768) Environmentally friendly 773) Slow drying 778) IJ02, IJ04, IJ21, contains: water, pigment, surfactant, 769) No odor 774) Corrosive IJ26 humectant, and biocide. 770) Reduced bleed 775) Pigment may clog nozzles 779) IJ27, IJ30 Pigments have an advantage in reduced 771) Reduced wicking 776) Pigment may clog actuator 780) Silverbrook, EP bleed, wicking and strikethrough. 772) Reduced strikethrough mechanisms 0771 658 A2 and 777) Cockles paper related patent applications 781) Piezoelectric inkjets 782) Thermal ink jets (with significant restrictions) Methyl Ethyl Ketone MEK is a highly volatile solvent used for 783) Very fast drying 785) Odorous 787) All IJ series ink (MEK) industrial printing on difficult surfaces 784) Prints on various 786) Flammable jets such as aluminum cans. substrates such as metals and plastics Alcohol (ethanol, 2- Alcohol based inks can be used where 788) Fast drying 792) Slight odor 794) All IJ series ink butanol, and the printer must operate at temperatures 789) Operates at sub-freezing 793) Flammable jets others) below the freezing point of water. An temperatures example of this is in-camera consumer 790) Reduced paper cockle photographic printing. 791) Low cost Phase change The ink is solid at room temperature, and 795) No drying time-ink 801) High viscosity 807) Tektronix hot (hot melt) is melted in the print head before jetting. instantly freezes on the print 802) Printed ink typically has a ‘waxy’ melt piezoelectric ink Hot melt inks are usually wax based, medium feel jets with a melting point around 80° C. After 796) Almost any print 803) Printed pages may ‘block’ 808) 1989 Nowak U.S. Pat. No. jetting the ink freezes almost instantly medium can be used 804) Ink temperature may be above the 4,820,346 upon contacting the print medium or a 797) No paper cockle occurs curie point of permanent magnets 809) All IJ series ink transfer roller. 798) No wicking occurs 805) Ink heaters consume power jets 799) No bleed occurs 806) Long warm-up time 800) No strikethrough occurs Oil Oil based inks are extensively used in 810) High solubility medium 813) High viscosity: this is a significant 815) All IJ series ink offset printing. They have advantages in for some dyes limitation for use in inkjets, which usually jets improved characteristics on paper 811) Does not cockle paper require a low viscosity. Some short chain (especially no wicking or cockle). Oil 812) Does not wick through and multi-branched oils have a sufficiently soluble dies and pigments are required. paper low viscosity. 814) Slow drying Microemulsion A microemulsion is a stable, self forming 816) Stops ink bleed 820) Viscosity higher than water 823) All IJ series ink emulsion of oil, water, and surfactant. 817) High dye solubility 821) Cost is slightly higher than water jets The characteristic drop size is less than 818) Water, oil, and based ink 100 nm, and is determined by the amphiphilic soluble dies can be 822) High surfactant concentration preferred curvature of the surfactant. used required (around 5%) 819) Can stabilize pigment suspensions

Ink Jet Printing

A large number of new forms of ink jet printers have been developed to facilitate alternative ink jet technologies for the image processing and data distribution system. Various combinations of ink jet devices can be included in printer devices incorporated as part of the present invention. Australian Provisional Patent Applications relating to these ink jets which are specifically incorporated by cross reference. The serial numbers of respective corresponding US patent applications are also provided for the sake of convenience. Australian Provisional US Patent/Patent Application Number Filing Date Title and Filing Date PO8066 15-Jul-97 Image Creation Method and Apparatus (IJ01) 6,227,652 (Jul. 10, 1998) PO8072 15-Jul-97 Image Creation Method and Apparatus (IJ02) 6,213,588 (Jul. 10, 1998) PO8040 15-Jul-97 Image Creation Method and Apparatus (IJ03) 6,213,589 (Jul. 10, 1998) PO8071 15-Jul-97 Image Creation Method and Apparatus (IJ04) 6,231,163 (Jul. 10, 1998) PO8047 15-Jul-97 Image Creation Method and Apparatus (IJ05) 6,247,795 (Jul. 10, 1998) PO8035 15-Jul-97 Image Creation Method and Apparatus (IJ06) 6,394,581 (Jul. 10, 1998) PO8044 15-Jul-97 Image Creation Method and Apparatus (IJ07) 6,244,691 (Jul. 10, 1998) PO8063 15-Jul-97 Image Creation Method and Apparatus (IJ08) 6,257,704 (Jul. 10, 1998) PO8057 15-Jul-97 Image Creation Method and Apparatus (IJ09) 6,416,168 (Jul. 10, 1998) PO8056 15-Jul-97 Image Creation Method and Apparatus (IJ10) 6,220,694 (Jul. 10, 1998) PO8069 15-Jul-97 Image Creation Method and Apparatus (IJ11) 6,257,705 (Jul. 10, 1998) PO8049 15-Jul-97 Image Creation Method and Apparatus (IJ12) 6,247,794 (Jul. 10, 1998) PO8036 15-Jul-97 Image Creation Method and Apparatus (IJ13) 6,234,610 (Jul. 10, 1998) PO8048 15-Jul-97 Image Creation Method and Apparatus (IJ14) 6,247,793 (Jul. 10, 1998) PO8070 15-Jul-97 Image Creation Method and Apparatus (IJ15) 6,264,306 (Jul. 10, 1998) PO8067 15-Jul-97 Image Creation Method and Apparatus (IJ16) 6,241,342 (Jul. 10, 1998) PO8001 15-Jul-97 Image Creation Method and Apparatus (IJ17) 6,247,792 (Jul. 10, 1998) PO8038 15-Jul-97 Image Creation Method and Apparatus (IJ18) 6,264,307 (Jul. 10, 1998) PO8033 15-Jul-97 Image Creation Method and Apparatus (IJ19) 6,254,220 (Jul. 10, 1998) PO8002 15-Jul-97 Image Creation Method and Apparatus (IJ20) 6,234,611 (Jul. 10, 1998) PO8068 15-Jul-97 Image Creation Method and Apparatus (IJ21) 6,302,528) (Jul. 10, 1998) PO8062 15-Jul-97 Image Creation Method and Apparatus (IJ22) 6,283,582 (Jul. 10, 1998) PO8034 15-Jul-97 Image Creation Method and Apparatus (IJ23) 6,239,821 (Jul. 10, 1998) PO8039 15-Jul-97 Image Creation Method and Apparatus (IJ24) 6,338,547 (Jul. 10, 1998) PO8041 15-Jul-97 Image Creation Method and Apparatus (IJ25) 6,247,796 (Jul. 10, 1998) PO8004 15-Jul-97 Image Creation Method and Apparatus (IJ26) 09/113,122 (Jul. 10, 1998) PO8037 15-Jul-97 Image Creation Method and Apparatus (IJ27) 6,390,603 (Jul. 10, 1998) PO8043 15-Jul-97 Image Creation Method and Apparatus (IJ28) 6,362,843 (Jul. 10, 1998) PO8042 15-Jul-97 Image Creation Method and Apparatus (IJ29) 6,293,653 (Jul. 10, 1998) PO8064 15-Jul-97 Image Creation Method and Apparatus (IJ30) 6,312,107 (Jul. 10, 1998) PO9389 23-Sep-97 Image Creation Method and Apparatus (IJ31) 6,227,653 (Jul. 10, 1998) PO9391 23-Sep-97 Image Creation Method and Apparatus (IJ32) 6,234,609 (Jul. 10, 1998) PP0888 12-Dec-97 Image Creation Method and Apparatus (IJ33) 6,238,040 (Jul. 10, 1998) PP0891 12-Dec-97 Image Creation Method and Apparatus (IJ34) 6,188,415 (Jul. 10, 1998) PP0890 12-Dec-97 Image Creation Method and Apparatus (IJ35) 6,227,654 (Jul. 10, 1998) PP0873 12-Dec-97 Image Creation Method and Apparatus (IJ36) 6,209,989 (Jul. 10, 1998) PP0993 12-Dec-97 Image Creation Method and Apparatus (IJ37) 6,247,791 (Jul. 10, 1998) PP0890 12-Dec-97 Image Creation Method and Apparatus (IJ38) 6,336,710 (Jul. 10, 1998) PP1398 19-Jan-98 An Image Creation Method and Apparatus 6,217,153 (IJ39) (Jul. 10, 1998) PP2592 25-Mar-98 An Image Creation Method and Apparatus 6,416,167 (IJ40) (Jul. 10, 1998) PP2593 25-Mar-98 Image Creation Method and Apparatus (IJ41) 6,243,113 (Jul. 10, 1998) PP3991  9-Jun-98 Image Creation Method and Apparatus (IJ42) 6,283,581 (Jul. 10, 1998) PP3987  9-Jun-98 Image Creation Method and Apparatus (IJ43) 6,247,790 (Jul. 10, 1998) PP3985  9-Jun-98 Image Creation Method and Apparatus (IJ44) 6,260,953 (Jul. 10, 1998) PP3983  9-Jun-98 Image Creation Method and Apparatus (IJ45) 6,267,469 (Jul. 10, 1998)

Ink Jet Manufacturing

Further, the present application may utilize advanced semiconductor fabrication techniques in the construction of large arrays of ink jet printers. Suitable manufacturing techniques are described in the following Australian provisional patent specifications incorporated here by cross-reference. The serial numbers of respective corresponding US patent applications are also provided for the sake of convenience. Australian Provisional US Patent/Patent Application Number Filing Date Title and Filing Date PO7935 15-Jul-97 A Method of Manufacture of an Image Creation 6,224,780 Apparatus (IJM01) (Jul. 10, 1998) PO7936 15-Jul-97 A Method of Manufacture of an Image Creation 6,235,212 Apparatus (IJM02) (Jul. 10, 1998) PO7937 15-Jul-97 A Method of Manufacture of an Image Creation 6,280,643 Apparatus (IJM03) (Jul. 10, 1998) PO8061 15-Jul-97 A Method of Manufacture of an Image Creation 6,284,147 Apparatus (IJM04) (Jul. 10, 1998) PO8054 15-Jul-97 A Method of Manufacture of an Image Creation 6,214,244 Apparatus (IJM05) (Jul. 10, 1998) PO8065 15-Jul-97 A Method of Manufacture of an Image Creation 6,071,750 Apparatus (IJM06) (Jul. 10, 1998) PO8055 15-Jul-97 A Method of Manufacture of an Image Creation 6,267,905 Apparatus (IJM07) (Jul. 10, 1998) PO8053 15-Jul-97 A Method of Manufacture of an Image Creation 6,251,298 Apparatus (IJM08) (Jul. 10, 1998) PO8078 15-Jul-97 A Method of Manufacture of an Image Creation 6,258,285 Apparatus (IJM09) (Jul. 10, 1998) PO7933 15-Jul-97 A Method of Manufacture of an Image Creation 6,225,138 Apparatus (IJM10) (Jul. 10, 1998) PO7950 15-Jul-97 A Method of Manufacture of an Image Creation 6,241,904 Apparatus (IJM11) (Jul. 10, 1998) PO7949 15-Jul-97 A Method of Manufacture of an Image Creation 6,299,786 Apparatus (IJM12) (Jul. 10, 1998) PO8060 15-Jul-97 A Method of Manufacture of an Image Creation 09/113,124 Apparatus (IJM13) (Jul. 10, 1998) PO8059 15-Jul-97 A Method of Manufacture of an Image Creation 6,231,773 Apparatus (IJM14) (Jul. 10, 1998) PO8073 15-Jul-97 A Method of Manufacture of an Image Creation 6,190,931 Apparatus (IJM15) (Jul. 10, 1998) PO8076 15-Jul-97 A Method of Manufacture of an Image Creation 6,248,249 Apparatus (IJM16) (Jul. 10, 1998) PO8075 15-Jul-97 A Method of Manufacture of an Image Creation 6,290,862 Apparatus (IJM17) (Jul. 10, 1998) PO8079 15-Jul-97 A Method of Manufacture of an Image Creation 6,241,906 Apparatus (IJM18) (Jul. 10, 1998) PO8050 15-Jul-97 A Method of Manufacture of an Image Creation 09/113,116 Apparatus (IJM19) (Jul. 10, 1998) PO8052 15-Jul-97 A Method of Manufacture of an Image Creation 6,241,905 Apparatus (IJM20) (Jul. 10, 1998) PO7948 15-Jul-97 A Method of Manufacture of an Image Creation 6,451,216 Apparatus (IJM21) (Jul. 10, 1998) PO7951 15-Jul-97 A Method of Manufacture of an Image Creation 6,231,772 Apparatus (IJM22) (Jul. 10, 1998) PO8074 15-Jul-97 A Method of Manufacture of an Image Creation 6,274,056 Apparatus (IJM23) (Jul. 10, 1998) PO7941 15-Jul-97 A Method of Manufacture of an Image Creation 6,290,861 Apparatus (IJM24) (Jul. 10, 1998) PO8077 15-Jul-97 A Method of Manufacture of an Image Creation 6,248,248 Apparatus (IJM25) (Jul. 10, 1998) PO8058 15-Jul-97 A Method of Manufacture of an Image Creation 6,306,671 Apparatus (IJM26) (Jul. 10, 1998) PO8051 15-Jul-97 A Method of Manufacture of an Image Creation 6,331,258 Apparatus (IJM27) (Jul. 10, 1998) PO8045 15-Jul-97 A Method of Manufacture of an Image Creation 6,110,754 Apparatus (IJM28) (Jul. 10, 1998) PO7952 15-Jul-97 A Method of Manufacture of an Image Creation 6,294,101 Apparatus (IJM29) (Jul. 10, 1998) PO8046 15-Jul-97 A Method of Manufacture of an Image Creation 6,416,679 Apparatus (IJM30) (Jul. 10, 1998) PO8503 11-Aug-97 A Method of Manufacture of an Image Creation 6,264,849 Apparatus (IJM30a) (Jul. 10, 1998) PO9390 23-Sep-97 A Method of Manufacture of an Image Creation 6,254,793 Apparatus (IJM31) (Jul. 10, 1998) PO9392 23-Sep-97 A Method of Manufacture of an Image Creation 6,235,211 Apparatus (IJM32) (Jul. 10, 1998) PP0889 12-Dec-97 A Method of Manufacture of an Image Creation 6,235,211 Apparatus (IJM35) (Jul. 10, 1998) PP0887 12-Dec-97 A Method of Manufacture of an Image Creation 6,264,850 Apparatus (IJM36) (Jul. 10, 1998) PP0882 12-Dec-97 A Method of Manufacture of an Image Creation 6,258,284 Apparatus (IJM37) (Jul. 10, 1998) PP0874 12-Dec-97 A Method of Manufacture of an Image Creation 6,258,284 Apparatus (IJM38) (Jul. 10, 1998) PP1396 19-Jan-98 A Method of Manufacture of an Image Creation 6,228,668 Apparatus (IJM39) (Jul. 10, 1998) PP2591 25-Mar-98 A Method of Manufacture of an Image Creation 6,180,427 Apparatus (IJM41) (Jul. 10, 1998) PP3989  9-Jun-98 A Method of Manufacture of an Image Creation 6,171,875 Apparatus (IJM40) (Jul. 10, 1998) PP3990  9-Jun-98 A Method of Manufacture of an Image Creation 6,267,904 Apparatus (IJM42) (Jul. 10, 1998) PP3986  9-Jun-98 A Method of Manufacture of an Image Creation 6,245,247 Apparatus (IJM43) (Jul. 10, 1998) PP3984  9-Jun-98 A Method of Manufacture of an Image Creation 6,245,247 Apparatus (IJM44) (Jul. 10, 1998) PP3982  9-Jun-98 A Method of Manufacture of an Image Creation 6,231,148 Apparatus (IJM45) (Jul. 10, 1998)

Fluid Supply

Further, the present application may utilize an ink delivery system to the ink jet head. Delivery systems relating to the supply of ink to a series of ink jet nozzles are described in the following Australian provisional patent specifications, the disclosure of which are hereby incorporated by cross-reference. The serial numbers of respective corresponding US patent applications are also provided for the sake of convenience. Australian US Patent/Patent Provisional Application and Number Filing Date Title Filing Date PO8003 15-Jul-97 Supply Method and 6,350,023 Apparatus (F1) (Jul. 10, 1998) PO8005 15-Jul-97 Supply Method and 6,318,849 Apparatus (F2) (Jul. 10, 1998) PO9404 23-Sep-97 A Device and 09/113,101 Method (F3) (Jul. 10, 1998)

MEMS Technology

Further, the present application may utilize advanced semiconductor microelectromechanical techniques in the construction of large arrays of ink jet printers. Suitable microelectromechanical techniques are described in the following Australian provisional patent specifications incorporated here by cross-reference. The serial numbers of respective corresponding US patent applications are also provided for the sake of convenience. Australian US Patent/Patent Provisional Application and Number Filing Date Title Filing Date PO7943 15-Jul-97 A device (MEMS01) PO8006 15-Jul-97 A device (MEMS02) 6,087,638 (Jul. 10, 1998) PO8007 15-Jul-97 A device (MEMS03) 09/113,093 (Jul. 10, 1998) PO8008 15-Jul-97 A device (MEMS04) 6,340,222 (Jul. 10, 1998) PO8010 15-Jul-97 A device (MEMS05) 6,041,600 (Jul. 10, 1998) PO8011 15-Jul-97 A device (MEMS06) 6,299,300 (Jul. 10, 1998) PO7947 15-Jul-97 A device (MEMS07) 6,067,797 (Jul. 10, 1998) PO7945 15-Jul-97 A device (MEMS08) 09/113,081 (Jul. 10, 1998) PO7944 15-Jul-97 A device (MEMS09) 6,286,935 (Jul. 10, 1998) PO7946 15-Jul-97 A device (MEMS10) 6,044,646 (Jul. 10, 1998) PO9393 23-Sep-97 A Device and 09/113,065 Method (MEMS11) (Jul. 10, 1998) PP0875 12-Dec-97 A Device (MEMS12) 09/113,078 (Jul. 10, 1998) PP0894 12-Dec-97 A Device and 09/113,075 Method (MEMS13) (Jul. 10, 1998)

IR Technologies

Further, the present application may include the utilization of a disposable camera system such as those described in the following Australian provisional patent specifications incorporated here by cross-reference. The serial numbers of respective corresponding US patent applications are also provided for the sake of convenience. Australian Provisional US Patent/Patent Application and Number Filing Date Title Filing Date PP0895 12-Dec-97 An Image Creation Method and Apparatus 6,231,148 (IR01) (Jul. 10, 1998) PP0870 12-Dec-97 A Device and Method (IR02) 09/113,106 (Jul. 10, 1998) PP0869 12-Dec-97 A Device and Method (IR04) 6,293,658 (Jul. 10, 1998) PP0887 12-Dec-97 Image Creation Method and Apparatus 09/113,104 (IR05) (Jul. 10, 1998) PP0885 12-Dec-97 An Image Production System (IR06) 6,238,033 (Jul. 10, 1998) PP0884 12-Dec-97 Image Creation Method and Apparatus 6,312,070 (IR10) (Jul. 10, 1998) PP0886 12-Dec-97 Image Creation Method and Apparatus 6,238,111 (IR12) (Jul. 10, 1998) PP0871 12-Dec-97 A Device and Method (IR13) 09/113,086 (Jul. 10, 1998) PP0876 12-Dec-97 An Image Processing Method and Apparatus 09/113,094 (IR14) (Jul. 10, 1998) PP0877 12-Dec-97 A Device and Method (IR16) 6,378,970 (Jul. 10, 1998) PP0878 12-Dec-97 A Device and Method (IR17) 6,196,739 (Jul. 10, 1998) PP0879 12-Dec-97 A Device and Method (IR18) 09/112,774 (Jul. 10, 1998) PP0883 12-Dec-97 A Device and Method (IR19) 6,270,182 (Jul. 10, 1998) PP0880 12-Dec-97 A Device and Method (IR20) 6,152,619 (Jul. 10, 1998) PP0881 12-Dec-97 A Device and Method (IR21) 09/113,092 (Jul. 10, 1998)

DotCard Technologies

Further, the present application may include the utilization of a data distribution system such as that described in the following Australian provisional patent specifications incorporated here by cross-reference. The serial numbers of respective corresponding US patent applications are also provided for the sake of convenience. Australian US Patent/Patent Provisional Application and Number Filing Date Title Filing Date PP2370 16-Mar-98 Data Processing Method 09/112,781 and Apparatus (Jul. 10, 1998) (Dot01) PP2371 16-Mar-98 Data Processing Method 09/113,052 and Apparatus (Jul. 10, 1998 (Dot02)

Artcam Technologies

Further, the present application may include the utilization of camera and data processing techniques such as an Artcam type device as described in the following Australian provisional patent specifications incorporated here by cross-reference. The serial numbers of respective corresponding US patent applications are also provided for the sake of convenience. Australian Provisional US Patent/Patent Application and Number Filing Date Title Filing Date PO7991 15-Jul-97 Image Processing Method and Apparatus 09/113,060 (ART01) (Jul. 10, 1998) PO7988 15-Jul-97 Image Processing Method and Apparatus 6,476,863 (ART02) (Jul. 10, 1998) PO7993 15-Jul-97 Image Processing Method and Apparatus 09/113,073 (ART03) (Jul. 10, 1998) PO9395 23-Sep-97 Data Processing Method and Apparatus 6,322,181 (ART04) (Jul. 10, 1998) PO8017 15-Jul-97 Image Processing Method and Apparatus 09/112,747 (ART06) (Jul. 10, 1998) PO8014 15-Jul-97 Media Device (ART07) 6,227,648 (Jul. 10, 1998) PO8025 15-Jul-97 Image Processing Method and Apparatus 09/112,750 (ART08) (Jul. 10, 1998) PO8032 15-Jul-97 Image Processing Method and Apparatus 09/112,746 (ART09) (Jul. 10, 1998) PO7999 15-Jul-97 Image Processing Method and Apparatus 09/112,743 (ART10) (Jul. 10, 1998) PO7998 15-Jul-97 Image Processing Method and Apparatus 09/112,742 (ART11) (Jul. 10, 1998) PO8031 15-Jul-97 Image Processing Method and Apparatus 09/112,741 (ART12) (Jul. 10, 1998) PO8030 15-Jul-97 Media Device (ART13) 6,196,541 (Jul. 10, 1998) PO7997 15-Jul-97 Media Device (ART15) 6,195,150 (Jul. 10, 1998) PO7979 15-Jul-97 Media Device (ART16) 6,362,868 (Jul. 10, 1998) PO8015 15-Jul-97 Media Device (ART17) 09/112,738 (Jul. 10, 1998) PO7978 15-Jul-97 Media Device (ART18) 09/113,067 (Jul. 10, 1998) PO7982 15-Jul-97 Data Processing Method and Apparatus 6,431,669 (ART19) (Jul. 10, 1998 PO7989 15-Jul-97 Data Processing Method and Apparatus 6,362,869 (ART20) (Jul. 10, 1998 PO8019 15-Jul-97 Media Processing Method and Apparatus 6,472,052 (ART21) (Jul. 10, 1998 PO7980 15-Jul-97 Image Processing Method and Apparatus 6,356,715 (ART22) (Jul. 10, 1998) PO8018 15-Jul-97 Image Processing Method and Apparatus 09/112,777 (ART24) (Jul. 10, 1998) PO7938 15-Jul-97 Image Processing Method and Apparatus 09/113,224 (ART25) (Jul. 10, 1998) PO8016 15-Jul-97 Image Processing Method and Apparatus 6,366,693 (ART26) (Jul. 10, 1998) PO8024 15-Jul-97 Image Processing Method and Apparatus 6,329,990 (ART27) (Jul. 10, 1998) PO7940 15-Jul-97 Data Processing Method and Apparatus 09/113,072 (ART28) (Jul. 10, 1998) PO7939 15-Jul-97 Data Processing Method and Apparatus 09/112,785 (ART29) (Jul. 10, 1998) PO8501 11-Aug-97 Image Processing Method and Apparatus 6,137,500 (ART30) (Jul. 10, 1998) PO8500 11-Aug-97 Image Processing Method and Apparatus 09/112,796 (ART31) (Jul. 10, 1998) PO7987 15-Jul-97 Data Processing Method and Apparatus 09/113,071 (ART32) (Jul. 10, 1998) PO8022 15-Jul-97 Image Processing Method and Apparatus 6,398,328 (ART33) (Jul. 10, 1998 PO8497 11-Aug-97 Image Processing Method and Apparatus 09/113,090 (ART34) (Jul. 10, 1998) PO8020 15-Jul-97 Data Processing Method and Apparatus 6,431,704 (ART38) (Jul. 10, 1998 PO8023 15-Jul-97 Data Processing Method and Apparatus 09/113,222 (ART39) (Jul. 10, 1998) PO8504 11-Aug-97 Image Processing Method and Apparatus 09/112,786 (ART42) (Jul. 10, 1998) PO8000 15-Jul-97 Data Processing Method and Apparatus 6,415,054 (ART43) (Jul. 10, 1998) PO7977 15-Jul-97 Data Processing Method and Apparatus 09/112,782 (ART44) (Jul. 10, 1998) PO7934 15-Jul-97 Data Processing Method and Apparatus 09/113,056 (ART45) (Jul. 10, 1998) PO7990 15-Jul-97 Data Processing Method and Apparatus 09/113,059 (ART46) (Jul. 10, 1998) PO8499 11-Aug-97 Image Processing Method and Apparatus 6,486,886 (ART47) (Jul. 10, 1998) PO8502 11-Aug-97 Image Processing Method and Apparatus 6,381,361 (ART48) (Jul. 10, 1998) PO7981 15-Jul-97 Data Processing Method and Apparatus 6,317,192 (ART50) (Jul. 10, 1998 PO7986 15-Jul-97 Data Processing Method and Apparatus 09/113,057 (ART51) (Jul. 10, 1998) PO7983 15-Jul-97 Data Processing Method and Apparatus 09/113,054 (ART52) (Jul. 10, 1998) PO8026 15-Jul-97 Image Processing Method and Apparatus 09/112,752 (ART53) (Jul. 10, 1998) PO8027 15-Jul-97 Image Processing Method and Apparatus 09/112,759 (ART54) (Jul. 10, 1998) PO8028 15-Jul-97 Image Processing Method and Apparatus 09/112,757 (ART56) (Jul. 10, 1998) PO9394 23-Sep-97 Image Processing Method and Apparatus 6,357,135 (ART57) (Jul. 10, 1998 PO9396 23-Sep-97 Data Processing Method and Apparatus 09/113,107 (ART58) (Jul. 10, 1998) PO9397 23-Sep-97 Data Processing Method and Apparatus 6,271,931 (ART59) (Jul. 10, 1998) PO9398 23-Sep-97 Data Processing Method and Apparatus 6,353,772 (ART60) (Jul. 10, 1998) PO9399 23-Sep-97 Data Processing Method and Apparatus 6,106,147 (ART61) (Jul. 10, 1998) PO9400 23-Sep-97 Data Processing Method and Apparatus 09/112,790 (ART62) (Jul. 10, 1998) PO9401 23-Sep-97 Data Processing Method and Apparatus 6,304,291 (ART63) (Jul. 10, 1998) PO9402 23-Sep-97 Data Processing Method and Apparatus 09/112,788 (ART64) (Jul. 10, 1998) PO9403 23-Sep-97 Data Processing Method and Apparatus 6,305,770 (ART65) (Jul. 10, 1998) PO9405 23-Sep-97 Data Processing Method and Apparatus 6,289,262 (ART66) (Jul. 10, 1998) PP0959 16-Dec-97 A Data Processing Method and Apparatus 6,315,200 (ART68) (Jul. 10, 1998) PP1397 19-Jan-98 A Media Device (ART69) 6,217,165 (Jul. 10, 1998) 

1. A printer assembly including: a pagewidth printhead; a recapping mechanism arranged to cap the pagewidth printhead during periods of non-use, the recapping mechanism including: a base portion; at least one solenoid coil fast with the base portion; and a capping portion arranged to cap and uncap the pagewidth printhead in response to operations of the solenoid coil.
 2. A printer assembly according to claim 1, wherein the at least one solenoid coil comprises a single elongate coil disposed on a surface of the base portion.
 3. A printer assembly according to claim 1, wherein the elongate coil is comprised of insulated wire wound about a ferrous member.
 4. A printer assembly according to claim 1, wherein the capping portion assumes a printhead capping position in response to cessation of current through the solenoid coil.
 5. A printer assembly according to claim 4, wherein the capping portion includes a biasing member arranged to force the capping portion to the capping position upon cessation of the current through the solenoid coil.
 6. A printer assembly according to claim 5, wherein the capping portion includes magnetically attractive material that is drawn to the solenoid coil upon application of current to the coil.
 7. A printer assembly according to claim 6, wherein the capping portion includes an elastomeric member arranged to form a seal about the pagewidth printhead in the capping position.
 8. A digital camera including a printer assembly according to claim
 1. 9. A digital camera including a printer assembly according to claim
 5. 